efficiency and effectiveness analysis of the …

Laura Delgado Díaz 1

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EFFICIENCY AND EFFECTIVENESS ANALYSIS OF THE INVENTORY SYSTEM IN A TESTING FACILITY BY APPLYING LEAN AND SIX SIGMA TOOLS

TRABAJO FIN DE MÁSTER PARA LA

OBTENCIÓN DEL TÍTULO DE MÁSTER

EN INGENIERÍA INDUSTRIAL

SEPTIEMBRE 2019

Laura Delgado Díaz

DIRECTOR DEL TRABAJO FIN DE MASTER:

Pablo Segovia Velasco

Efficiency and effectiveness analysis of the inventory system in a testing facility by applying Lean and Six Sigma tools


RESUMEN Este Trabajo de Fin de Máster ha sido desarrollado con el objetivo de analizar la

eficiencia y efectividad de un laboratorio de pruebas de una empresa de componentes

mecánicos, mediante la aplicación de metodologías Lean y Six Sigma. El foco se pondrá en

su sistema de gestión de inventario, el cual se encarga de la manipulación y seguimiento de los

prototipos empleados en las pruebas.

La empresa estudiada se encarga del diseño, fabricación y mejora de distintos

componentes mecánicos para la industria de la automoción. Debido a que la naturaleza y detalle

de dichos componentes no es relevante para el presente proyecto, no será detallado. El nombre

de la empresa tampoco se mencionará por motivos de confidencialidad.

Es una compañía mediana que posee una estructura jerarquizada, dividida en distintos

departamentos. Entre ellos, caben destacar el departamento de Mecánica y el Laboratorio de

Pruebas, los cuales deben trabajar de manera coordinada en las etapas de diseño y mejora para

validar los productos creados en la empresa. Para ello se empLean prototipos y distintos bancos

de ensayo capaces de realizar pruebas mecánicas de distinta naturaleza.

El laboratorio de pruebas está dividido a su vez en el laboratorio técnico y el

laboratorio operacional, los cuales se encargan del mantenimiento de los bancos de ensayo y de

la planificación de las distintas pruebas, respectivamente. Es también tarea del laboratorio

operacional, y, en particular, de los coordinadores de pruebas, el asegurar que los prototipos se

encuentran localizados y disponibles y que las distintas pruebas mecánicas pueden realizarse.

Los coordinadores de pruebas supervisan a su vez las distintas operaciones de los prototipos y

del laboratorio, y aseguran la disponibilidad de personal y material para realizar los procesos.

En la Figura 1 se puede observar la estructura de dicho laboratorio.

Figura 1 - Estructura del laboratorio de pruebas

Laboratorio de pruebas

Laboratorio técnico

Desarrollo de bancos de

ensayo

Ingenieros de montaje

Ingenieros de hardware y

software

Soporte y procesos

Laboratorio operacional

Coordinadores de pruebas

Operaciones de prototipos

Montaje de prototipos

Operaciones del laboratorio

Ingenieros de pruebas

Mecánicos

RESUMEN

4 Escuela Técnica Superior de Ingenieros Industriales (UPM)

En la empresa se realizan diferentes procesos, desde la oferta y negociación hasta la

obtención del producto final y su posterior venta. Para el presente trabajo, los más relevantes

serán los procesos relacionados con el laboratorio de pruebas, los cuales son Montaje, Prueba

y Validación. El montaje y desmontaje de prototipos se realiza en el departamento de

Operaciones, y su relevancia reside en asegurar que dichos componentes cumplen los

requerimientos de montaje antes de una prueba, o en detectar fallos mecánicos tras haber sido

probados. Las pruebas mecánicas se desarrollan en los bancos de ensayo, y los resultados de

las mismas se envían al departamento de Desarrollo para su posterior validación.

Por lo tanto, los pasos a seguir para realizar una prueba son los siguientes, tal y como se

muestra en la Figura 2: el ingeniero de desarrollo solicita la realización de una prueba y envía

la orden al laboratorio. A continuación, el coordinador de pruebas se encarga de planificar dicha

prueba y asegurar la disponibilidad de los recursos necesarios para la misma. Dichos recursos

son el requerimiento de la prueba, el personal, el banco de ensayos, el montaje, la secuencia de

la prueba y el prototipo. Una vez todos esos elementos están disponibles, el ingeniero de

pruebas realiza la prueba y comparte sus resultados con el ingeniero de desarrollo.

Figura 2 - Pasos a seguir a la hora de realizar una prueba

El laboratorio de pruebas posee 16 bancos de ensayo diferentes, con al menos un

ingeniero de pruebas encargado de cada banco. Debido al elevado coste e importancia de los

bancos, es un objetivo clave de la empresa el maximizar su utilización. Además de los bancos

de ensayo, el laboratorio de pruebas posee un área de montaje y desmontaje de los prototipos y

tres áreas destinadas a su almacenaje.

Una vez analizada la empresa y el laboratorio de pruebas, es posible detectar el

principal problema que se intentará resolver en esta tesis. Durante los últimos años, la empresa

se ha visto envuelta en un proceso de rápida expansión y crecimiento que ha causado que el

funcionamiento de algunos procesos en el laboratorio no sea el óptimo. Se han detectado

diversas ocasiones en las que los bancos de ensayos no pueden realizar alguna prueba y uno de

los principales motivos es la ausencia de prototipo.

Pese a que hay diferentes áreas de almacenaje, su función no está siempre clara y se dan

situaciones en las que los prototipos son almacenados de forma incorrecta. Esta falta de

transparencia y trazabilidad dificulta el hecho de localizarlos antes o después de haber realizado

una prueba, causando esperas y tareas adicionales a los empleados encargados de encontrarlos.

Crear una orden (INGENIERO DE DESARROLLO)

Planificar la orden (COORDINADOR

DE PRUEBAS)

Preparar la prueba (COORDINADOR DE

PRUEBAS)

Realizar la prueba (INGENIERO DE

PRUEBAS)



Por tanto, el objetivo de este proyecto consiste en analizar cómo la aplicación de

metodologías Lean y Six Sigma puede resultar beneficiosa para mejorar el rendimiento del

laboratorio de pruebas, así como incrementar la trazabilidad y localización de los prototipos.

Con esto se pretende llegar a un mejor entendimiento acerca de cómo un control ineficiente del

inventario puede afectar a los procesos en el laboratorio y sus consecuencias económicas.

Más específicamente, los objetivos del trabajo consisten en la definición y análisis de

los distintos procesos del Laboratorio e identificación de sus desperdicios y sus causas. Así

mismo, se tienen que estudiar las posibles formas de mitigar el efecto de los desperdicios

detectados mediante la aplicación de herramientas Lean. Adicionalmente, se deben ofrecer

propuestas basadas en dicha metodología, definiendo los pasos necesarios para su

implementación y realizando un estudio económico de viabilidad. Finalmente, dichos pasos

deben llevarse a cabo siguiendo Six Sigma.

Antes de comenzar con el desarrollo de la solución, es necesario definir algunos

conceptos claves para este proyecto, tales como el control de inventario, los sistemas de

inventario, las metodologías Lean y Six Sigma y sus herramientas más relevantes.

Desarrollar un adecuado control de inventario es una tarea clave para cualquier

empresa. El mantener la cantidad adecuada de elementos almacenados, en el lugar adecuado y

en el momento adecuado, juega un papel crucial a la hora de satisfacer la demanda y disminuir

costes. Los costes de inventario son los asociados con los costes de pedido, los costes de

almacenaje y los costes de falta de stock.

Para controlar el inventario de forma adecuada, se utilizan los sistemas de inventario.

Dichos sistemas se encargan de contabilizar y organizar el inventario, así como de mejorar su

trazabilidad y registrar los movimientos de cada uno de sus elementos.

La metodología Lean surgió en los años 30 cuando la empresa Toyota creó el Sistema

de Producción de Toyota (TPS), mejorando las ideas de integración de procesos de Henry Ford.

Dicho sistema, que se ha convertido en el ejemplo Lean mundial, se basa en la mejora continua

y optimización de procesos mediante la eliminación de actividades que no aportan valor.

Asimismo, con la eliminación de dichas actividades, denominadas desperdicios o mudas, se

logra un aumento de la calidad y una notable disminución de costes.

Lean se considera una filosofía de trabajo, compuesta de un conjunto de técnicas que, a

la hora de ser implantadas, suponen tanto un alto nivel de compromiso por parte de la dirección

de la compañía, como un profundo cambio cultural en su organización. Los distintos posibles

desperdicios que pueden localizarse en cualquier empresa, según Lean, son los mostrados en

la Figura 3.

RESUMEN


Figura 3 - 7 posibles desperdicios o mudas

Para eliminar dichos desperdicios, se puede utilizar un elevado número de

herramientas Lean, las cuales se pueden implantar de forma independiente o conjunta. Las

más relevantes para este trabajo son:

• VSM: en inglés, Value Stream Mapping o mapas de flujo de valor, se utilizan

para ver y representar las distintas etapas de un proceso, con el objetivo de

detectar fallos y oportunidades de mejora.

• Análisis de causa y efecto: se utilizan para relacionar los distintos desperdicios

con sus posibles causas. Uno de los más comunes es el diagrama de Ishikawa o

de espina de pez.

• PDCA: en inglés, hace referencia a Plan, Do, Control, Act, y es una herramienta

basada en la aplicación de cuatro etapas para la mejora continua de procesos,

productos y servicios.

• Flujo continuo: el objetivo de esta herramienta es el diseño de procesos cuyas

etapas se suceden de manera continua, minimizando las esperas y eliminando

los defectos.

• Estandarización de procesos: elaboración de instrucciones que ilustren el

mejor método para realizar las tareas de manera adecuada.

• 5S: busca la eficiencia de las personas en su área de trabajo, mediante la

búsqueda del orden, limpieza y organización. Consta de 5 etapas, originalmente

en japonés, que marcan las pautas para lograr dicha organización: Sort

(clasificación), Seiton (organización), Seiso (limpieza), Seiketsu

(estandarización) y Shitsuke (disciplina).

• Kaizen: busca el incremento de la productividad y la búsqueda de la mejor

continua, mediante la estandarización del trabajo y la documentación de las

mejores prácticas.

Sobreproducción

Fabricación de productos innecesarios.

Esperas

Tiempos que algunos procesos deben

permanecer inactivos debido al proceso

anterior.

Transporte

Innecesario movimiento de

materiales.

Movimiento

Innecesario movimiento de los

trabajadores.

Reprocesos

Realización de más procesos de los

requeridos para obtener el producto solicitado

por el cliente.

Inventario

Exceso de productos que sobrepasa las necesidades de la

empresa.

Defectos

Productos que necesitan arreglos o reparaciones, o que

tienen que ser descartados.



• Kanban: el objetivo de esta herramienta es la mejora de la trazabilidad,

colaboración y accesibilidad de la información mediante tablas Kanban capaces

de representar el estado de las tareas en tiempo real.

Pese a que la filosofía Lean surgió originalmente con el objetivo de optimizar procesos

de producción, es también aplicable al resto de procesos en las empresas. Los beneficios de

incluir el pensamiento Lean en control de inventarios son, entre otros, la disminución de niveles

de inventario, el incremento de los estándares en materiales y procesos, la mejora de

colaboraciones y una reducción general en costes.

Six Sigma se define como una metodología cuyo objetivo es mejorar la calidad a través

de la identificación y eliminación de las causes de defectos. Se originó inicialmente en Motorola

y posteriormente desarrollada en GE en 1990. Para lograr Six Sigma estadísticamente, un

proceso no debe producir más de 3.4 defectos por millón de oportunidades, considerando

defecto como todo aquello que no cumple con los requerimientos del cliente y oportunidad, la

posibilidad de que se dé un defecto.

Una de las herramientas más usadas y relevantes de la metodología Six Sigma es

DMAIC. Sus siglas en inglés (Define, Measure, Analysis, Improve y Control) se refieren a 5

fases interconectadas que se usan para definir y mejorar procesos existentes. Esta metodología

ha sido la empleada a lo largo del trabajo en la discusión y obtención de los resultados.

La primera parte de la obtención de los resultados y su discusión consiste en un

análisis de la estructura. Se corresponde con las primeras etapas de Definición y Medición

(Define y Measure) de la metodología DMAIC, y consiste en la creación de un mapa de flujo

de valor de los distintos procesos realizados al probar un prototipo, para detectar posibles

retrasos y cuellos de botella.

Para crear el mapa, ha sido necesario recabar información de los empleados del

laboratorio en contacto con los prototipos: los coordinadores de pruebas, los trabajadores del

departamento de montaje, los ingenieros de pruebas y los mecánicos del laboratorio, encargados

de montar y desmontar los prototipos en los bancos de ensayo. Pese a que los coordinadores de

pruebas, encargados de asegurar que todos los elementos necesarios para las pruebas estén

listos, son los responsables de los prototipos, son múltiples las ocasiones en las que los

mecánicos deben buscar los componentes ellos mismos. Los técnicos de montaje pueden

compartir su visión relativa al tratamiento de los prototipos en el departamento de montaje, y

los ingenieros de pruebas pueden ofrecer información de primera mano sobre las pruebas que

se realizan, cómo se reciben y se entregan los prototipos antes y después de las pruebas, y cómo

registran su estado.

RESUMEN


Una vez obtenida dicha información, el proceso de creación del mapa se divide en 5

etapas: decidir su alcance, definir los procesos, indicar los flujos de información, recabar la

información crítica y añadirla junto con los tiempos al mapa. Con ello, se obtienen dos mapas,

uno de situación ideal y otro real, cuya comparación permite detectar las ineficiencias del

laboratorio de pruebas relacionadas con el control de los prototipos. Se observa que dichas

ineficiencias están relacionadas con el incremento de las esperas entre procesos, las cuales están

vinculadas con los tiempos de búsqueda de los prototipos. Se ha detectado un escenario en el

que las dificultades para localizar prototipos son más comunes, y es el caso de prototipos que

tienen que ser probados por segunda o tercera vez y no se guardó un registro adecuado de su

última localización tras la anterior prueba. Al día, se ha observado que se dedica al menos una

hora en buscar algún prototipo.

Tras obtener el flujo de mapa de valor, y, como parte de la etapa de Análisis (Analysis)

de DMAIC, se pasa a la identificación de los desperdicios o mudas existentes en el laboratorio.

Se observa que, debido a las esperas entre procesos, la trazabilidad insuficiente de los prototipos

y la repetición de procesos innecesarios, los desperdicios más significativos son las Esperas, el

Movimiento y los Reprocesos. El principal problema causado por estas mudas es el retraso del

tiempo de inicio de alguna prueba, lo que conlleva la inutilización del banco de ensayo,

causando importantes impactos económicos y, en el peor de los casos, ocasionando retrasos en

el envío de los resultados al cliente.

Los desperdicios detectados están relacionados con dos problemas en particular: las

dificultades al encontrar un prototipo y la repetición innecesaria de procesos. Para entender

mejor las causas de dichos problemas, se lleva a cabo un análisis de causa y efecto mediante

dos diagramas de Ishikawa.

Entre las causas más comunes de no hallar un prototipo se encuentran la falta de

estandarización e información relativa a la localización de los prototipos, los descuidos y

olvidos de los empleados, la comunicación deficiente y la falta de un sistema de inventario

adecuado que registre los movimientos de los prototipos.

En cuanto a la repetición de procesos, se observan causas similares, también

relacionadas con la ausencia de estándares y de un sistema de registro de las acciones de los

prototipos y los problemas de comunicación entre empleados.

Una vez detectados los desperdicios y analizados las causas de sus problemas

relacionados, se inicia la etapa de Mejora (Improve) de DMAIC, en la cual se ofrecen soluciones

para mitigar el efecto de dichas mudas.



Se ha detectado que, debido a la trazabilidad deficiente de los prototipos, las esperas son

frecuentes entre procesos del laboratorio, ocasionando retrasos e incumplimiento de los tiempos

de entrega. Para disminuir dichas esperas, se ofrecen tres acciones posibles: mejorar la

sincronización entre procesos, mejorar la fiabilidad de los procesos y reducir las faltas de

tiempo mediante un incremento de la eficiencia. Para ello, se propone la utilización de dos

herramientas Lean: flujo continuo y estandarización de procesos.

Debido a que las pruebas no se solicitan ni se realizan a una frecuencia constante, lograr

el flujo continuo en el laboratorio no es tarea fácil. Sin embargo, hay una serie de prácticas que

pueden emplearse para favorecer el flujo continuo. Entre ellas, destaca un aumento de la

consistencia al realizar las pruebas, ya que no debería ser posible empezar una nueva prueba

hasta que el prototipo de la prueba anterior esté colocado en su sitio y sus resultados hayan sido

propiamente registrados. Asimismo, todos los empleados deberían ser conscientes de la

importancia de mantener la organización de los prototipos. Con ello, se lograría incrementar la

frecuencia y calidad del envío de resultados al cliente, y disminuir las esperas.

La estandarización de procesos se puede lograr aplicando la herramienta Kaizen de

mejora continua. Esta herramienta utiliza cuatro etapas, denominadas DAMI: Define, Achieve,

Maintain y Improve. Primero se define un estándar con un objetivo a conseguir y se asegura

que dicho estándar es comprendido por los empleados del laboratorio. Una vez logrado dicho

estándar, debe ser posible mantenerlo. Finalmente, se pasa a la etapa de mejora de dicho

estándar y se vuelve a la primera etapa de nuevo. Mediante la definición de estándares

relacionados con el número de prototipos perdidos o fuera de sitio, se puede lograr la

disminución de los tiempos de espera en el laboratorio.

Para reducir el movimiento innecesario de los empleados en el laboratorio, se ofrecen

dos soluciones, las cuales son la disminución de tiempo de viaje entre procesos (por ejemplo,

entre tomar el prototipo y llevarlo al banco de ensayo en el que se requiere), y la eliminación

de acciones innecesarias (recorrer el laboratorio de arriba a abajo con el objetivo de encontrar

un prototipo).

Una herramienta Lean muy útil para reducir este desperdicio es 5S, la cual está

directamente relacionada con la mejora de la eficiencia de los trabajadores y el aumento del

orden en el laboratorio. Las 5S se deben aplicar en el siguiente orden: primero debe hacerse una

lista con todos los prototipos del laboratorio para detectar cuáles son realmente necesarios y

cuáles se pueden descartar (Sort), a continuación, deben ordenarse y colocarse en posiciones

de fácil acceso, para reducir esperas (Seiton). El siguiente paso es mantener limpio el área de

trabajo, para así facilitar la identificación de problemas (Seiso), y posteriormente incluir

MUDA 1

MUDA 2

RESUMEN


estándares para mantener los prototipos en posición y el laboratorio en orden (Seiketsu).

Finalmente, el último paso consiste en implementar disciplinas y hábitos para mantener las

mejoras y los estándares a largo plazo (Shitsuke).

Algunas de las soluciones para eliminar los reprocesos son la aclaración de los

estándares y expectativas de los clientes con anticipación, la confirmación de que todos los

procesos que se realizan son necesarios para lograr dichas expectativas y el uso apropiado de

procesos. Aunque éste es el desperdicio que sucede con menos frecuencia en el laboratorio, la

repetición de pruebas en un prototipo de manera innecesaria puede conllevar daños mecánicos

que lo hagan invalido para futuras pruebas. Para prevenir y eliminar este desperdicio puede

utilizarse la herramienta Lean Kaizen tal y como se sugiere para la Muda 1.

Mediante la combinación de herramientas Lean y Six Sigma, se pueden ofrecer

soluciones adicionales con el fin de eliminar los desperdicios detectados y mejorar la

trazabilidiad y organización de los prototipos. Dichas soluciones consisten en la Integración de

Sistemas y la Automatización Parcial del laboratorio, y están basadas en la filosofía Kaizen de

búsqueda de la mejora continua.

La integración de sistemas es una propuesta que consiste en la centralización de la

información proveniente de las distintas herramientas de planificación y seguimiento utilizadas

en el laboratorio. Su objetivo es mejorar la calidad de la información, incrementar la visibilidad

y productividad, disminuir esperas y aumentar la capacidad de reacción en caso de ineficiencias.

Todo ello, mediante la combinación de herramientas Lean, tales como flujo continuo y Kanban.

Como previamente se ha mencionado, esta propuesta unifica la información de tres

herramientas: el Diario de seguimiento de prototipos, en el que los ingenieros de pruebas deben

registrar los movimientos diarios del banco de ensayo, así como el prototipo que se utiliza; el

Plan global de pruebas, en el que los coordinadores de pruebas planifican los futuros tests; y,

las Peticiones de montaje, mediante el cual se pueden solicitar acciones de montaje o

desmontaje de los prototipos. La unión de dichas herramientas en un único sistema de Estado

de prototipos, equivalente a un sistema de inventario, permite obtener una imagen global de los

procesos del laboratorio, así como llevar un mejor seguimiento de las pruebas y los prototipos.

El elemento más importante de dicho sistema es la Matriz de estado de los prototipos.

Dicha matriz representa el estado de los prototipos a lo largo del tiempo, a fin de detectar

tendencias y corregir errores. Se define como estado físico de un prototipo la comparación entre

su localización actual y su localización requerida. Hay cuatro posibilidades diferentes de

estados: “En posición”, “Realizando una prueba”, “Posición errónea” y “Desconocido”. El

MUDA 3



funcionamiento de la matriz es muy similar a una tabla Kanban, ya que permite organizar el

trabajo desde un nivel organizativo y acceder al estado de los prototipos en cualquier momento.

La información de dicha matriz se debe registrar en un conjunto de bases de datos, entre

las que destacan la base de datos de Prototipos, la de Lugares de almacenamiento, la de

Distribuidores y la de Usuarios. Las bases de datos deben estar interconectadas y se tienen que

actualizar cada vez que se registre algún cambio en el sistema. Entre los posibles cambios

destacan: cambio en el estado de un prototipo, registro de un nuevo prototipo, realización de

una prueba en un prototipo, movimientos… La utilización de bases de datos para visualizar la

información en una tabla Kanban, favorece la metodología de flujo continuo y mejora continua.

Con la automatización parcial del laboratorio se busca la disminución del error

humano y la mejora de la trazabilidad. Se apuesta por el uso de etiquetas y lectores de radio

frecuencia RFID para identificar tanto los prototipos como los distintos lugares de almacenaje.

Esta propuesta complementa a la integración de sistemas ya que ofrece información actualizada

sobre la localización de los prototipos y promueve el flujo continuo.

Para llevar a cabo la propuesta, primero es necesario aplicar la metodología 5S para

identificar los distintos prototipos, clasificarlos y asignarles lugar de almacenaje. Asimismo, se

requiere de una reestructuración y redefinición de los posibles almacenes en el laboratorio de

pruebas. Una vez realizados dichos pasos, se asignan etiquetas RFID a cada uno de los

prototipos y se colocan lectores en la entrada de los posibles almacenes y bancos de ensayo. De

esta manera, quedaría registrado cada movimiento realizado por los prototipos, siendo posible

actualizar la base de datos con su último estado.

Una vez definida la etapa de Mejora de DMAIC, se finaliza con la etapa de Control, en

la que se definen indicadores para asegurar el mantenimiento de las soluciones propuestas.

Dichos indicadores se denominan KPI o Key Performance Indicators, y se dividen en

“Indicadores rezagados” e “Indicadores líderes”, en función de si la información que analizan

es histórica o actual, respectivamente. Para la presente tesis se han utilizado datos sobre el

estado de 25 prototipos en el período comprendido entre el 27 de octubre de 2018 y el 31 de

mayo de 2019.

Los Indicadores rezagados arrojan información muy valiosa a la hora de detectar

tendencias históricas y saber cómo el control de inventario de los prototipos ha funcionado a lo

largo del tiempo. Los Indicadores líderes, por el contrario, analizan los últimos resultados

registrados en el sistema para obtener su funcionamiento actual. Entre la información de mayor

valor que pueden proporcionar se encuentra el porcentaje de prototipos en localizaciones

erróneas o desconocida. Se observa que, para el 31 de mayo, un 36% de los prototipos de la

muestra seleccionada se encuentran en una posición errónea, y del 16% se desconoce su

posición. Para asegurar la trazabilidad y control de los prototipos, debería ser objetivo común

del laboratorio el minimizar dichos porcentajes.

RESUMEN


Una vez definidas las propuestas, se sugieren pasos a seguir para su implementación, la

cual se podría llevar a cabo en un tiempo estimado de 68 días, y se analiza su viabilidad

económica. Comparando los costes estimados de la implementación y mantenimiento del

sistema de Estado de prototipos con los costes actuales incurridos, se observa que podría

lograrse una significante reducción de costes desde el año siguiente a su implantación. Dicha

reducción de costes iría incrementando con los años, pudiendo lograr un ahorro estimado de

133.827 € en el quinto año.

Tras finalizar la etapa de resultados y discusión, se estudian los diferentes impactos que

el proyecto podría causar en sociedad. Dichos impactos son principalmente legales (licencias

de los programas utilizados), profesionales (mejora del rendimiento de los trabajadores,

incremento de la calidad de la comunicación, etc.) y económicos (las propuestas solucionadas

podrían suponer ahorros significativos para la empresa).

Se concluye que, pese a las limitaciones existentes, se ha logrado satisfactoriamente el

objetivo de este proyecto: el análisis de la aplicación de metodologías Lean y Six Sigma para

mejorar los procesos en un laboratorio de pruebas y eliminar sus desperdicios. Se ha justificado

también cómo un control ineficiente del inventario puede afectar a los procesos en el laboratorio

y qué consecuencias económicas acarrea. El desarrollo de la solución se ha llevado a cabo

siguiendo la metodología DMAIC de Six Sigma.

Como opciones de mejora futuras, algunas de las sugeridas son el llevar a cabo la

implementación de las sugerencias propuestas, realizar la difusión del pensamiento Lean a lo

largo de la empresa, la creación de una interfaz de usuario e incorporación de más

funcionalidades en el sistema de Estado de prototipos, etc.

Por último, se realiza un estudio de la planificación temporal del proyecto y un estudio

económico del mismo. El proyecto se ha llevado a cabo en un intervalo de 11 meses, y se han

empleado un total de 377 horas en su realización. Económicamente, teniendo en cuenta la mano

de obra y el equipamiento, supondría unos costes totales de 13.631,32 €

To my professor Pablo, for his interest in the project since the very beginning, it would

not have been possible without your patience, guidance and help

To my abuelo and my yayo, who have always loved me and support me, and who I

miss every day…, I just hope to make you feel proud

To the rest of my family, for all your encouragement and love, even from the distance,

I have never really felt far away from home. Specially to my cousin Sofía, for being brave

enough to join me in this new crazy chapter and for all the laughs, cries and unconditional

support

To my friends, to the ones they have been always there and to the new ones with whom

I am sharing these new adventures

And finally, to my colleagues, for their help, guidance, patience and good energy,

I can feel really lucky to work with you

Thank you so much

Laura Delgado Díaz

September 2019 - Ghent, Belgium

ABSTRACT

Lean and Six Sigma methodologies were introduced in the 40’s and the 80’s,

respectively. Since then, the number of companies that have implemented their tools in order

to enhance their efficiency and quality has not cease to grow. Both are defined as Continuous

Improvement methods that pursue operational excellence and customer satisfaction.

The purpose of this Master thesis has been to analyse the performance and efficiency of

a testing lab in a company specialized in mechanical components for the automotive industry.

By using concepts from Lean and Six Sigma, there have been spotted the different challenges

faced by the facilities and have been offered different suggestions to improve their processes.

To properly comprehend those processes, a combination of observations and interviews

has formed the main source of information throughout the project. A theoretical framework

constituted by the prevailing theory on Lean and Six Sigma has been linked and merged with

those observations.

After acknowledging that one of the highest-value processes is the management and

tracking of the testing prototypes, a discussion has been started from that point. There have

been approached the wastes by using tools such as VSM or Root-cause analysis. Subsequently,

the provided recommendations are in the form of standardized processes, 5S or Kaizen.

Moreover, there have been suggested two additional innovative solutions whose aim is to

improve planning, schedule and tracking, through continuous flow, Kanban tools and PDCA

approaches. The whole discussion has been carried out adopting the Six Sigma DMAIC

method.

Furthermore, there have been successfully detected the existing bottleneck processes,

identified their influence, and provided recommendations to mitigate their effect.

Keywords: Lean, Six Sigma, wastes, Inventory Control, Inventory Systems, testing lab,

mechanical prototypes

Unesco nomenclature:

• 3310.99 Industrial Technology

• 1207.08 Inventory

• 1207.10 Network flow

• 1207.13 Scheduling

• 3310.03 Industrial processes

• 5311.07 Operations research



TABLE OF CONTENTS

1. INTRODUCTION ................................................................................................ 23

1.1. Background ..................................................................................................... 23

1.1.1. Structure of the company .......................................................................... 23

1.1.2. Processes in the company ......................................................................... 26

1.1.3. Testing facilities ....................................................................................... 28

1.2. Problem description ........................................................................................ 31

1.3. Purpose ........................................................................................................... 31

1.4. Structure of the Thesis .................................................................................... 31

2. OBJECTIVES ...................................................................................................... 33

2.1. General objectives .......................................................................................... 33

2.2. Specific objectives .......................................................................................... 34

3. STATE OF THE ART ......................................................................................... 35

3.1. Inventory Control ........................................................................................... 35

3.2. Introduction to Inventory Systems ................................................................. 36

3.3. Lean thinking .................................................................................................. 37

3.3.1. Seven wastes ............................................................................................. 38

3.3.2. Lean tools ................................................................................................. 39

3.3.2.1. Value Stream Mapping ....................................................................... 39

3.3.2.2. Root cause analysis ............................................................................. 39

3.3.2.3. PDCA approach .................................................................................. 39

3.3.2.4. Continuous flow .................................................................................. 39

3.3.2.5. Standardized work .............................................................................. 39

3.3.2.6. 5S ........................................................................................................ 40

3.3.2.7. Kaizen ................................................................................................. 40

3.3.2.8. Kanban ................................................................................................ 40

3.3.3. Lean applied to inventory control ............................................................. 41

3.4. Six Sigma ........................................................................................................ 41

TABLE OF CONTENTS


3.4.1. DMAIC ..................................................................................................... 42

4. METHODOLOGY .............................................................................................. 43

4.1. Initial study ..................................................................................................... 43

4.2. Project preparation .......................................................................................... 44

5. RESULTS AND DISCUSSION .......................................................................... 45

5.1. Structure analysis ............................................................................................ 45

5.1.1. VSM.......................................................................................................... 45

5.1.2. Muda (waste) identification ...................................................................... 52

5.1.3. Root cause analysis ................................................................................... 54

5.2. Design of the solution ..................................................................................... 57

5.2.1. PDCA approach ........................................................................................ 57

5.2.2. Waste 1: waiting ....................................................................................... 58

5.2.2.1. Continuous flow .................................................................................. 58

5.2.2.2. Standardized work .............................................................................. 59

5.2.3. Waste 2: motion ........................................................................................ 59

5.2.3.1. 5S ........................................................................................................ 59

5.2.4. Waste 3: over processing .......................................................................... 60

5.2.4.1. Kaizen ................................................................................................. 61

5.2.5. Additional solutions .................................................................................. 61

5.2.5.1. System Integration .............................................................................. 61

5.2.5.2. Partial automatization and tracking .................................................... 70

5.2.5.3. KPIs .................................................................................................... 79

5.2.5.4. Steps for their implementation ............................................................ 86

5.2.5.5. Economic feasibility ........................................................................... 88

5.3. Legal, professional and economic impacts ..................................................... 92

6. CONCLUSIONS .................................................................................................. 93

6.1. General conclusions ........................................................................................ 93

6.2. Specific conclusions ....................................................................................... 94

6.3. Limitations ...................................................................................................... 96

7. FUTURE WORK ................................................................................................. 97

8. TEMPORAL PLANNING AND PROJECT BUDGET ................................... 99



8.1. Temporal Planning ......................................................................................... 99

8.2. Work Breakdown Structure .......................................................................... 102

8.3. Project Budget .............................................................................................. 103

9. REFERENCES ................................................................................................... 105

10. ABBREVIATIONS AND ACRONYMS ...................................................... 109

List of figures ............................................................................................................ 111

List of tables .............................................................................................................. 113

APPENDIX 1: RFID tags and readers ................................................................... 115

APPENDIX 2: Estimated parameters for the Economic Feasibility Study ........ 117

APPENDIX 3: Interview guide ............................................................................... 119

TABLE OF CONTENTS




Chapter 1.

INTRODUCTION

1. INTRODUCTION

The purpose of this first chapter is to give a general view of the framework of this Master

thesis, as well as the problems expected to be solved and the objectives that want to be achieved.

There will be also included an overview of all the different chapters and parts in which this

thesis is divided.

1.1. Background

The main function of any testing facility is to accomplish quality and performance

checks of products, in order to give feedback to its clients. Since it provides qualitative and

quantitative output about their performance, it is a key part of any manufacturing company,

especially in design and validation stages. Therefore, it is critical to optimize the effectiveness

and efficiency of its processes.

This chapter’s goal is to contribute to a global understanding about how the company

works, its structure, which are its processes and a final focus on the Testing facilities.

1.1.1. Structure of the company

The studied company is a mechanical company specialized in the design, manufacture

and testing of different assemblies and components for the high-performance automotive

industry. It is a medium size company with ~1500 employees, founded in the 70s that serves a

global client base thanks to its operations based in North America and Europe. For the present

project, the characteristics of those types of car components are not relevant and therefore they

will not be detailed. For confidentiality reasons, the name of the company will not be mentioned

either.

The structure of the company is a hierarchical organization, whose employees are

ranked in different levels within the company, each level being above another one. To ease the

control of the different processes, each level is led by a person who is responsible of several

workers. This structure is followed in all the departments of the company, clearly defining the

role of every employee and their relationship with the rest of the employees. It is a centralized

INTRODUCTION


structure, which means that higher management is often responsible for taking the most

important decisions.

To have a more precise idea, in Figure 1 it is possible to see an overview of the

company’s organization, and its different main departments.

Figure 1 - Structure of the company

As a head of the company there is the manager director, who makes sure all the

departments are aligned and functioning properly. He is responsible for the daily operations of

the company and is also expected to keep the company solvent, as well as to promote its

innovation and expansion within the industry. Below the director, it is possible to find some

key departments such as Mechanics, the department of Controls and the Testing Lab.

The Mechanics department oversees the design and production of the different

products from the company, and is divided in three sub departments: Development, Systems

and CAD. Development is responsible for defining the products and their characteristics, and

ensure it follows the client requirements –design wise-. The Systems department has to make

sure the different subsystems of the product work, and how to achieve that; in the CAD

department they are responsible of the mechanical design of the components of the product, as

well as of the theoretical materials, strengths, resistance and mechanical tests of them.

In the Controls department they are focused on the performance of the whole system

and how every part of the product interacts with the rest. Furthermore, it is also a core task of

the department to prepare the software in the system to be as autonomous and intelligent as

possible.

For the scope of this master thesis, the most important department would be the Testing

Lab. In this department there are performed mechanical tests to validate the quality and

functionality of the product, so it is one of the most critical departments of the company. The

Manager Director

Mechanics

Development Systems CAD

Controls Testing Lab

Operational Lab

Technical Lab



Mechanics department and, in particular, the Development department, is the direct responsible

of requesting and detailing the tests that have to be performed. The Testing Lab is divided in

the Technical Lab, responsible of the instrumentation and controls; and the Operational Lab.

Figure 2 - Structure of the Testing Lab

The test lab is organizationally structured as shown in the Figure 2. As mentioned, it has

two main subdivisions: the Technical Lab and the Operational Lab. The Technical Lab must

maintain the test benches and the necessary equipment to perform the tests, whereas the

Operational Lab acts more directly on the product itself, making sure that test runs and validates

the quality of the product.

As previously mentioned, the Technical Lab oversees the maintenance of the Test

benches, it must ensure their quality and availability. The different tests are run in the test

benches, so it is critical to keep them in the optimal conditions, making sure they work

according to the specifications. Since the company runs high performance mechanical tests for

the automotive industry, it is always primordial to keep the safety in the Lab.

As a part of this department, there is the Test Bench Development department and

Support and Processes department. The Test Development Department has two types of

engineers: Test Setup Engineers and Hardware and Software Engineers. The first ones must

make sure the setup is correct before starting any test, which means, the Test Bench is in good

conditions and is successfully equipped with all the required sensors and elements specified in

the Test. The second group of engineers, Hardware and Software engineers, provide the

Testing Lab

Technical Lab

Test Bench Development

Test Setup Engineers

Hard. & Soft. Engineers

Support & processes

Operational Lab

Tests coordination

Prototype Operations

Prototype Assembly

Lab Operations

Test BenchesLab

Mechanics

INTRODUCTION


necessary tools such as required electronic devices or programming modules to make sure the

test can be programmed, and the CPU is communicated with the test bench. The Support and

Processes Department manages the different test benches and makes sure the specifications

related with quality and security issues are fulfilled.

The Operational Lab is responsible of managing the different products that are going

to be tested and planning the different tests. The head of the department is closely in contact

with the tests coordinators, whose main function is to plan the different tests, ensuring not only

the availability of the products that are going to be tested, but also the readiness of the sequence,

the test request, the test bench and the staff. Inside the Operational Lab, there are also two sub-

departments: Prototype Operations Department and Lab Operations Department. In Prototype

Operations they are mainly responsible of the assembly and disassembly of all the different

parts and products, evaluating them by visual inspection and reporting the results to the Test

Coordinators. Lab Operations Department is divided in the Test Benches and the Lab

Mechanics. The Test Benches are the physical location where the tests are done and they are

direct responsibility of the Test Engineers, whereas the Test Mechanics are the staff responsible

of mounting the different products to test, as well as to ensure the mechanical status of the

Benches.

1.1.2. Processes in the company

The different stages before selling any product, from the product concept to

manufacturing, are the ones shown in the Figure 3:

Figure 3 - Processes in the company

Offer and negotiation

Definition of the product

Final design, development and research

CAD

CAMTesting of the

prototypeProduction Assembly

Testing ValidationDevelopment

of the product

Final product and selling



1. Offer and negotiation: there is a meeting between the company and the client where

the client determines his requirements and specifications regarding the product. If both

sides come to an agreement, the project is signed.

2. Definition of the product: the second step is to define in detail all the parts of the

product, according to the client’s specifications. That means, define not only which

elements are going to be in the product, but also which departments should be involved

in the process. There are some aspects that need to be consider such as:

a. The reliability of the product.

b.What would be the manufacturing costs, keeping in mind the price

agreed with the client to leave room for profit.

c. The complexity of the manufacture, considering all the components that

conform the product.

d.Determination of the materials that are going to be needed for

production.

3. Final design, development and research: include all the needed materials and

dimensions of the product, editing the design as much as necessary. All vital details

should be included.

4. Computer-aided design: also known as CAD, in this step the goal is to develop a

computer model of the final design, by using 3D rendering software. By doing so, it is

possible to detect and reveal any potential issues that were not obvious during the

product design stage.

5. Computer-aided manufacturing: simulate the manufacturing process of the different

components and products, using computer simulation software.

6. Testing of the prototype: in this step the main goal is to check the behaviour of the

prototype, making sure it works as expected, and, if any issue is detected, schedule the

necessary amendments on the design that should be done to correct it.

7. Production: once the prototype has passed the tests and there are no more issues to

solve, the next step is to proceed with the manufacturing of the product. Some of the

decisions that should be taken at this stage are the materials that are needed, the batch

number and the manufacturer. For the studied company, the manufacturing process is

done internally for the majority of the components of the product.

8. Assembly: the scope of this step is to gather all the different manufactured parts and

build the final product.

9. Testing: once the product has been manufactured and assembled it is time to do rigorous

tests to validate it. Those tests will be requested by the Development department, as

mentioned before, and they will take place in the Testing Lab.

10. Validation: the Test Engineers have to send the results of the tests to the Development

department, who is the responsible of the validation of those tests. If the validation

process is not successful, it might be necessary to redesign some parts of the product

and to develop specific tests to investigate the root causes of the issues.

INTRODUCTION


11. Development of the product: once the validation process is completed, the product can

start to be manufactured.

12. Final product and selling: the clients –mainly automotive brands- receive the product

after the manufacturing, which will be ready for them to include it in their vehicles and

try their behaviour and performance.

This project will be focused on the analysis of the Testing stages, mainly, but also

indirectly in the Assembly and Validation stages.

1.1.3. Testing facilities

The tests in the testing lab are processed following the structure shown in Figure 4:

Figure 4 - Tests requesting process

1. Create an order: first an order from Engineering (development department) is

created, requesting for a test to be performed, to check the behaviour for

validation a specific mechanical component. The order is detailed in a document

called Test Request, where is stated the Unit where the test should be performed,

the tools and sensors to use, the different steps to follow while testing and the

results that are expected.

2. Plan the order: afterwards, the order is sent to the Test Lab Coordinators, whose

task is now to plan the test, when and where it has to be performed, which tools

are needed, and who would be the responsible people (Test Engineers, Test

Bench Engineers, Test Mechanics) involved in the test. The test coordinator

must plan the test starting day, the end day, as well as the tests that must be

performed before and after. To plan those starting and ending date he asks for

input from the Test Engineer. The goal would be to keep the test bench as less

idle as possible.

3. Prepare the test: as mentioned before, it is also duty of the Test Lab Coordinator

to make sure that the planned dates are reached. In the Figure 5 it is possible to

see a schematic overview of all the different elements that need to be aligned

and ready before starting every test. Therefore, before the test starting date, the

Create order (ENGINEERING)

Plan the order (LAB COORD)

Prepare the test (LAB COORD)

Test (LAB ENGINEER)



Test Bench Coordinator has to make sure the sequence is ready (Test engineers),

the test bench will be ready (Test Bench Engineers), the tools and prototype to

test will be ready (Engineering and Test Mechanics), as well as the necessary

staff to monitor and make sure the test runs.

Figure 5 - Test readiness requirements

4. Test: the test engineer would be responsible of preparing and starting the test,

supervising its performance and keeping the requestors informed about the

results. Once the test has been done (it can end up as FAILED or SUCCEEDED),

the tested prototype is taken out of the Test bench and the Test Bench Engineers

and Test Mechanics should make sure the bench is ready for the following

planned test.

The physical place in the company where the tests are performed is called the Test Lab.

This place is divided in different regions by functionality: Test Benches, Assembly zones, and

Storage areas.

In total, 16 test benches are allocated in the Test Lab. At least one test engineer is

responsible of every test bench. These benches develop different mechanic tests, and it is key

for the company to minimize their idle time as much as possible. The idle time (and therefore

the delays) from the benches can come from different causes, as explained before: test sequence

not ready, test bench or test request not ready, prototype to test not ready, setup not ready and

lack of staff. The warehouse of the Test Lab should be ready to avoid the lack of the materials

needed for the Setup and ensure the readiness of the prototypes, and it should make sure all the

elements are localized and ready to use before starting any test.

The Assembly zones are the physical areas where the different mechanical components

and parts are mounted or disassembled. They are directly linked with the Test benches and the

warehouse, since the parts need to be ready before the tests start, and there should be also room

TEST READY

Test Request

Staff

Setup

Prototype

Test Sequence

INTRODUCTION


for disassembly in case it is required after a test is done, or the test fails. To sum up, in Assembly

there are two processes: assembly and disassembly of the parts, which are explained further in

detail:

• Assembly: it is a process required every time a test is going to be performed and

every time a component has been disassembled and needs to be mounted again

to carry on with testing or shipment.

• Disassembly: this process might be required when a test finishes and it is

specified by the requesters to analyse it internally, or when a test fails, and it is

necessary to check the interior of the component in order to analyse the root

causes better.

In Figure 6 it is possible to see a schematic view of the Test Lab, divided in the

different areas. The areas in blue (TU) represent the different Test cells or Test Units, the area

in orange (AW) is the Assembly workshop and the areas in green (WH) represent the different

storage locations. Currently, WH1 is used to temporary store items such as some prototypes

that have arrived. WH2 is used for obsolete prototypes that are not really needed and WH3 has

space for some critical prototypes that must be stored there for a while. The yellow areas

represent the working area of the Test Engineers controlling the different tests and the white

area is currently a free space. The grey areas represent space dedicated to other departments.

The whole area of the facilities is around 6000m2 and its perimeter is approximately 300 meters.

The longest distance (in diagonal), is 114 meters. Therefore, it takes less than 5 min to walk

from any point to any other point within the facilities.

Figure 6 - 2D map of the Testing Facilities



1.2. Problem description

Due to the fast grow of the company, and its rapid increase of human and materials

resources, the performance of the Testing facilities is often not optimal. The main goal of the

facilities is to minimize the idle time of the test benches, due to their high costs. However, there

are several situations where the test bench cannot run a test and one of the most common causes

is the lack of testing prototype.

Although there are several storage areas, their function is not often clear and there are

misunderstandings and errors made when storing a prototype before or after a test. That lack of

transparency and poor tracking of the items lead to many situations where the employees

struggle to find the prototypes to test.

1.3. Purpose

The purpose of this project is to analyse the benefits of applying Lean thinking and Six

Sigma principles in the Testing facilities. Therefore, the goal is to increase the knowledge about

those methodologies and apply their tools to study, characterize and try to improve the

performance of the Test Lab, by mainly focusing on the prototypes’ management. This will

lead to a better understanding of how a poor control of the inventory can affect the different

processes in the Testing facilities and its economic consequences.

1.4. Structure of the Thesis

Chapter 2 presents the general and specific objectives pursued by the Thesis.

Chapter 3 provides an overview about the state of the art, mainly related with Inventory

Control, Lean methodologies and Six Sigma.

Chapter 4 states the methodology that has been followed in order to successfully

accomplish the objectives of this thesis.

Chapter 5 shows the obtained results, analyses and provides a detailed discussion about

them.

Chapter 6 describes the major findings as conclusions.

Chapter 7 suggests future work that could overcome the limitations of this thesis.

Chapter 8 presents the planning over time as well as the budget that would have to be

spent when performing this type of project.

The last two chapters, 9 and 10, state the References, Abbreviations and Acronyms used

in the project. Finally, there are also collected the list of tables and figures; as well as three

appendixes.

INTRODUCTION




Chapter 2.

OBJECTIVES

2. OBJECTIVES

The objectives throughout this thesis can be classified in two categories, general

objectives, which provides a global overview of what needs to be achieved, and specific

objectives, more focused on providing a more detailed description of all the steps that need to

be followed in order to accomplish the general objectives.

2.1. General objectives

The main aim of this project is to deeply analyse the different processes that occurs in

the Test Lab and detect how the management of the testing components affects its performance.

Once done that, and based on a proper theoretical background, it is possible to suggest different

solutions that will improve the normal functioning of the activities in the facilities and its

control of inventory.

It will be necessary to properly identify the wastes that occur and use Lean tools to

propose ways of reducing or eliminating them. The whole identification and search of the

solution will be carried out by following the DMAIC methodology from Six Sigma (Define,

Measure, Analyse, Improve and Control).

OBJECTIVES


2.2. Specific objectives

To make sure the general objectives are achieved, it is necessary to define the specific

objectives, which will be related with the different stages of the Project:

1. Define, measure and analyse the current processes in the Testing facilities by using

Lean tools.

2. Identify the different wastes related with the prototypes and existing in the facilities

and carry on a root cause analysis.

3. Study the solution to mitigate the effect of each one of the wastes, by applying

different and specific Lean tools.

4. Propose alternative solutions based on Lean and Six Sigma methods.

5. Define and describe those proposals and its needed elements.

6. Define the necessary steps to successfully implement both proposals.

7. Analyse the economic feasibility of the proposals.

8. To perform all the previous stages, follow the Six Sigma methodology to identify

and search for the solution.



Chapter 3.

STATE OF THE ART

3. STATE OF THE ART

The objective of this chapter is to provide a basic background about Inventory Control

and its importance for the companies, an overview of Inventory Systems, as well as Lean

thinking and its applications in warehousing. Finally, it will be explained the main

characteristics of Six Sigma and how is it beneficial for companies.

3.1. Inventory Control

For any company, one of the most important logistic drivers in its Supply Chain is the

Inventory. The challenge of having the right number of elements stored in the right place, in

the right moment, is key to face the customer demands and decrease the costs of the company.

Inventory Control can be considered as essential to improve service and reduce costs, and it

determines how good a company manages its working capital to maintain a consistent and

adequate cash flow [1].

There are three different types of inventory costs, which are the following:

o Ordering costs: cost of purchasing a new item for the company.

o Holding costs: cost of money tied up in inventory, such as the cost of

capital or the opportunity cost of the money [2]. Moreover, it also considers:

▪ Cost of the physical space occupied by the inventory including

rent, depreciation, utility costs, insurance, taxes, etc.

▪ Cost of handling the items.

▪ Cost of deterioration and obsolescence.

o Shortage costs: costs of running out of inventory in stock [3]. These costs

include:

▪ Loss of time and delays

▪ Costs of pilferage, obsolescence and shrinkage

▪ Costs of misuse of the workforce

▪ Loss of potential sales

STATE OF THE ART


Through a proper Inventory Control, the main objective is to minimize the costs related

with holding too much unnecessary inventory and shortage of items (not enough stock to meet

the demand). Therefore, it is critical for any company to calculate the right number of products

while coping with the uncertainty of the Supply Chain. As shown in the Figure 7, the holding

costs and the ordering costs are key to obtain the optimal amount of products (Q*) that need to

be purchased to minimize the total costs.

Figure 7 - Optimum batch size in Inventory Control

3.2. Introduction to Inventory Systems

As mentioned, it is a crucial challenge for every company to find the optimal and most

suitable system to manage its inventory. Inventory management is responsible of the inventory

system of a company, which is an element of the supply chain and it refers more specifically

to processes such as storing, ordering and using a company’s inventory. It is also included the

management of raw materials, components and finished products [4].

Inventory systems also ease the process of organizing and managing multiple items in

several locations. Although there are multiple types of inventory system, which can vary in

their individual design, feature set and operations, they all share some basic capabilities [5], as

shown in the Figure 8.



Figure 8 - Basic characteristics of inventory systems

Therefore, for most companies, implementing a proper Inventory System is a key

activity that has a huge impact in its daily operations and financial statements.

3.3. Lean thinking

The core idea of Lean thinking is to gradually work on eliminating waste from the

company’s processes [6]. Every activity that does not add any value from the client’s

perspective is considered as a muda or waste. A Lean organization understands the customer

value and focus its efforts and processes to continuously increase it.

In 1913, Henry Ford came up with a solution to integrate his entire production process.

In the 1930s, and based on Ford’s idea, in Toyota they invented the Toyota Production

System, which became the leading Lean exemplar in the world.

This system mainly moved the focus of the manufacturing engineer from individual

machines and their utilization, to the flow of the product through the total process. Toyota stated

that it would be possible to decrease the costs, increase the variety and quality, as well as to

obtain very rapid throughput times to respond to changing customer desires by [7]:

• Properly sizing the machines for the actual volume needed.

• Implementing self-monitoring machines to ensure quality.

•The system must always be aware of all the items stored in the company. It should not only provide a total count of inventories, but also data related with the amount of inventory allocated in a specific location

Count

•It is common that most items do not stay in a single location. In order to obtain a precise inventory count, an inventory system must be able to track the movement from one location to another.

Track

•Keeping a proper record of the transactions associated with inventory management is key for companies to avoid financial issues and inaccurate inventory numbers.

Record

•Inventory systems are able to manage the inventory’s characteristics such as how much inventory to order, order cycle, supplier information, production costs, product lead time, lot-size availability, product units of measurement, among others.

Manage

STATE OF THE ART


• Aligning the machines up in process sequence.

• Pioneering quick setups so each machine could make small volumes of many

part numbers.

• Having each process step notify the previous step of its current needs for

materials.

This could also help to make the information management much simpler and more

accurate. Toyota turned into the largest automaker in the world, considering the overall sales,

which made it stand as the strongest proof of the power of Lean enterprise.

Since Lean thinking is unstoppably being spread across the world, its tools have been

adapted beyond manufacturing, to distribution and logistics, services, retail, healthcare,

construction, maintenance, and even government.

3.3.1. Seven wastes

As previously explained, the main idea of Lean is to eliminate everything and anything

which is not adding value for the customer. There are identified 7 main areas of waste, that are

typically known as the 7 deadly wastes [8]:

• Overproduction: manufacturing a product before it is needed, which leads to

extra inventory and an increase of storage costs.

• Waiting: time that some of the processes must be on hold for the previous

transaction.

• Transport: avoidable movement of raw materials, finished goods or work-in-

progress.

• Motion: unnecessary movement of people.

• Over-processing: do more processing that is needed to produce what is required

by the customer.

• Inventory: quantities of different products (such as raw materials, work in

process or finished goods), that exceed the needs of the company.

• Defects: deficiencies in products that need some rework, or they are scrap.

A highly relevant form of waste that is not included in seven wastes is the unused

human potential. This waste causes the loss of many opportunities, as, for instance, the lack

of motivation, the lack of creativity and the lack of ideas. To avoid and eliminate this eighth

waste, it is normally advisable to develop strong coaching skills for managers that can end up

being very effective in strengthening employee contributions.



3.3.2. Lean tools

There is an extensive collection of Lean tools, which can eliminate the different wastes

and improve the company operations. The most relevant Lean tools for this project will be

explained in this chapter.

3.3.2.1.Value Stream Mapping

A Value Stream Mapping o VSM is a tool used to visually plot the flow of different

processes. Shows the current and expected state of steps highlighting opportunities for

improvement. This Lean tool can expose the waste in the current processes and offer a roadmap

for development through the future state. [6]

3.3.2.2.Root cause analysis

Ishikawa diagrams: This technique, published by Kaoru Ishikawa in 1990 [9], clearly

plots the root causes of the problem. Moreover, it is also a useful tool for uncovering bottlenecks

in a process and identifying why a process is not working. [10]

3.3.2.3.PDCA approach

PDCA, also known as the ‘Deming Wheel’, is a four-stage Lean tool for continually

improving processes, products or services. It was developed by Dr William Edwards Deming

in the 1950s., and it provides a simple and effective way of solving problems and managing

change. [11]

PDCA stands for Plan, Do, Check and Act, which are four steps that should be followed

in order the get the highest quality results in our solutions.

3.3.2.4.Continuous flow

The objective of this tool is to design processes whose flow is continuous and the

number of buffers between steps have been minimized or eliminated. [12] By implementing

continuous flow, it is possible to eliminate many forms of waste, such as inventory, waiting,

time and transport.

3.3.2.5.Standardized work

The goal of this Lean tool is to use standardized work instructions to ensure the use of

a consistent method and consistent times for each step of production. [13] Standardized work

is also defined as the basis of operations to make sure the products are made in the easiest,

safest and most effective way based on the current technologies and formulas. [14]

STATE OF THE ART


3.3.2.6.5S

5S is a strategy based on the CANDO1 system developed by Henry Ford at the beginning

of the 20th century [15]. 5S stands for the Japanese words used to describe the steps of a

workplace organization process: Seiri (sort), Seiton (Set in order), Seiso (Shine), Seiketsu

(Standardize) and Shitsuke (Sustain). Those steps need to be taken in the mentioned order, as

shown in the Figure 9.

Figure 9 - 5S steps

3.3.2.7.Kaizen

The name of this philosophy comes from a Japanese term meaning “change for the

better” or “continuous improvement”. It should be necessary to document the current best

practice to define the standardized work that will form the baseline for continuous

improvement. Once that standard has been improved, a new standard will become the baseline

for further improvements, and so on, [16] following the PDCA cycle.

3.3.2.8.Kanban

Kanban is a Lean tool which stands for improving the traceability, collaboration and

accessibility of information. It represents work items on a Kanban board, that allows team

members to check the state of every piece of work at any time. Those boards can either be

1CANDO system: C=cleaning up, A=arranging, N=neatness, D=discipline and O=ongoing improvement



physical or digital and their task is to ensure the team’s work is visualized, their workflow is

standardized, and all issues or dependencies can be immediately identified and resolved. [17]

3.3.3. Lean applied to inventory control

When it comes to inventory control it is also possible to apply Lean techniques, since

they help companies to reduce costs, improve flexibility and have more time to spotlight the

customers’ needs. For instance, by applying Lean tools to control the inventory, it is possible

to obtain some benefits such as:

• Decrease of storage units and inventory levels

• Increase of the standards in materials and processes

• Improvement of collaborations

• Overall reduction in costs

Therefore, Lean supply chain and inventory management enable companies to improve

efficiency and increase profits. [18]

3.4. Six Sigma

Six Sigma is defined as an improved method whose goal is to maximize quality through

the identification and elimination of sources of defects. It was initially originated in Motorola

and further developed by GE in the 1990s. In order to statistically achieve Six Sigma, a process

shall not produce more than 3.4 defects per million opportunities, as represented in the Figure

10. A Six Sigma defect can be defined as anything that is not aligned with the customer

specifications, and an opportunity is considered as the total number of chances for a defect [19].

Figure 10 - Six Sigma distribution

STATE OF THE ART


3.4.1. DMAIC

DMAIC, which stands for Define, Measure, Analysis, Improve and Control, is an

essential part of a company’s Six Sigma programme, and it is mainly used to assess and improve

existing processes. The actions that define its name are linked with five interconnected phases,

which will be explained further in detail [20]:

1. Define: the first step consists on identifying and selecting the right project, as well

as selecting its boundaries and goals.

2. Measure: gather data to determine the “current state” of the project. That data is

referred to key process characteristics, the scope of parameters and their

performances.

3. Analyse: interpret the data to identify key causes and process determinants. If the

result is not what expected, its design can be modified and restart in the “Measure”

stage.

4. Improve: change the process by addressing and eliminating the root causes, in order

to optimize its performance.

5. Control: implement procedures to ensure the gains are sustained.

In Figure 11 there are schematically represented the stages of the DMAIC methodology [21].

Figure 11 - DMAIC Methodology

Define

Measure

Analyse

Design acceptance?

Improve

Control

Redesign



Chapter 4.

METHODOLOGY

4. METHODOLOGY

The general methodology that has been followed to obtain the results of this thesis is the

Six Sigma DMAIC method. This methodology, which includes definition of measurement,

improvement and control, provides a structure framework for solving business issues by

following an effective process execution. [22]

In this chapter it will be detailed how it was the initial study and the preparation that it

was necessary to carry out the project.

4.1. Initial study

The idea for this Master Thesis got born while working as a test engineer in a mechanical

lab. It was noticed that some processes were not working properly and there was some

misunderstandings and problems in the testing facilities due to the control of the assets in the

inventory. That seemed challenging so the decision of analysing the prototypes’ warehouse and

the different processes related with it, in order to give some ideas to try to improve its

performance was taken. By merely observation, analysis of the historical data, and different

interviews with responsible people inside the company, all combined with personal experience

and effects observed while performing the different tests, it was possible to come to a more

precise idea about how the warehouse was working. In the APPENDIX 3: Interview guide,

there are exposed the different questions that were asked during the interviews.

METHODOLOGY


4.2. Project preparation

The preparation for the project was divided in two stages. The first stage consisted on

getting familiar with all the technical knowledge that it was required for the project. During that

stage, it was necessary to investigate about Supply Chain Management and its logistical and

cross-functional drivers, Lean thinking and Six Sigma, Warehouse Management Systems and

latest and modern inventory issues and solutions, such as automatization or system integration.

The second stage was mainly focused on the gathering of information about the Testing

facilities. It was analysed in detail how the Testing facilities were working, the elements that

they were being stored in the different storage locations, how was the division of

responsibilities, the main complaints from the employees and issues they were facing, as well

as the details about the physical distribution of the facilities. To obtain a more detailed

understanding of how the management of the prototypes was being handled, it was selected one

test bench as a reference and deeply analysed all its activities during a 10-month interval. Once

done that, it was possible to apply all the theoretical knowledge in the real-life example.



Chapter 5.

RESULTS AND DISCUSSION

5. RESULTS AND DISCUSSION

The aim of this chapter is to describe the different phases followed to obtain the results.

Those are the structure analysis, the design of the solution and the legal, professional and

economic impacts caused by the project.

5.1. Structure analysis

The scope of this chapter will be to analyse the structure of the testing facilities by

applying Lean thinking and tools such as VSM or root cause analysis. By doing so, it will be

possible to properly identify the existing wastes in that specific department in the company.

Once that has been achieved, the objective of the following chapter: “Design of the solution”,

will be to find solutions to minimize those wastes.

5.1.1. VSM

Value Stream Maps are particularly valuable for representing the flow of production and

highlighting opportunities for improvement. By creating a VSM that represents the processes

of the testing facilities the objective is to easily detect which are the bottlenecks and where do

they occur. A VSM can be as complex as wanted, so therefore is especially important to

determine beforehand which are the process adding the highest value. In this case, it has been

analysed all the process followed when testing a prototype, in order to look for possible delays

or restrains. Since the testing process is similar in every test bench, the results obtained can be

extrapolated to every single prototype tested in the company.

To carry out the mapping [23], it has been used first-hand information coming from

representatives of different departments. Since they have a realistic perspective on how things

are done, it is possible to obtain an objective status of the system and the different processes,

and spot real problems on it. Considering that the objective of this project is to detect how the

inventory control of the prototypes is affecting the testing processes, it was necessary to gather

information from representatives of departments in contact with the prototypes and in charge



of their tracking. For that reason, it was key to have the perspective of Test coordinators,

Prototype Technicians, Test Engineers and Lab Mechanics. In the Figure 12 is shown the

Testing Lab structure, highlighting the departments of the mentioned representatives. The

representatives in Test coordination, the Test coordinators, could offer information related with

all the stages that the prototypes go through since their entrance in the company till they are

stored or sent to the client. The representatives in Prototype Assembly, the Prototype

Technicians, could offer their vision related with the handling and treatment of the prototypes

in assembly. The representatives in the Test Benches, the Test Engineers, provided first-hand

vision of the different tests that are carried in their Test Bench, how the prototypes are received

and delivered after testing, and how their test status is logged. The Lab Mechanics could also

offer output about the difficulties they encounter to find prototypes. Once that information was

gathered, was possible to start mapping.

Figure 12 - Prototype stakeholders in the Testing Facilities

The process of creating the VSM using the gathered information has been carried out

following different stages. In the Figure 13 is possible to see the final VSM obtained.

1. Decide how far to go

Firstly, it was necessary to indicate a start and end point, to show where the internal

processes begin and ends. The start point is stated at the pickup of the prototypes,

not only from external suppliers but also from internal ones, for the cases where re-

testing of prototypes is carried out.

Testing Lab

Technical Lab

Test Bench Development

Test Setup Engineers

Hard. & Soft. Engineers

Support & processes

Operational Lab

Tests coordination

Prototype Operations

Prototype Assembly

Lab Operations

Test Benches Lab Mechanics



The end point is determined as the delivery or storage of the prototype and the

sharing of the information with the customer, a Test requestor from Development

department.

2. Define the processes

Secondly, there has been determined all the different processes that the prototype

goes through to get from the start to the end point and they add value along the way.

Those processes are:

1) Functionality check 1: once the prototype has been delivered from the

supplier, it must go through a process to check if it has the necessary

functionality requirements to be tested. This process is typically carried out

in a Test Bench specialized in End of Line (EoL) testing.

2) Testing: if the prototype successfully passes the Functionality check, it is

handed from the EoL bench to the test bench where the required test needs

to be performed. The information related with that test must be provided by

the Engineering department in advance.

3) Functionality check 2: once the test has been done, it is typically requested

to carry out a second functionality check to confirm the results and prove the

prototype is still passing the functionality requirements.

4) Disassembly: afterwards, it is common to realize some physical checks of

the prototype in the Assembly department, to add as information to the Test

results.

5) Storage: finally, the last stage is to properly store the prototype. Depending

on the result of the test and the type of prototype, as well as the future

planning for that prototype, there must be designed some specialized areas

for its storage.

3. Indicate the Information Flows

The Information Flows are represented in the top part of the VSM. The Engineering

Department (the customer), needs to communicate the Testing Lab which test want

to perform, and Testing Control needs to align when, where, how and with which

prototype that test can be performed. If it is a prototype that needs to be provided by

an external supplier, the Testing department needs to contact him and align the date

and way of the delivery. However, if it is a prototype that has been already tested

and it is already allocated in the testing facilities, they need to have it localized and

align the date and way of the delivery as well to the test engineer.



Considering the testing process is not a process following a Continuous flow, the

frequency of those Information Flows is variable, depending on the requirements of

the Engineering department.

4. Gather the critical data

Once all the basic structure has been determined it was necessary to specify some

critical data for each process. For this case, the relevant information to gather was

the location of the processes, the number of shifts done and the total time of

availability per day. As well, it was also important to include the transfer time and

the cycle times. Since they are flexible processes, depending on the request, the

determined cycle times are an average of the real ones. For the testing process, since

it can take from less than 10 mins to months and it is not possible to shorten or

optimize it, the cycle time has not been considered. The transfer time before and

after testing processes considers the mounting and dismounting time of the prototype

by a Mechanic in the Test Bench, as well as the receiving time. That receiving time

is defined as the amount of time that it takes to find the prototype in the facilities,

take it from that location and move it to the new one. Since the facilities have a

relatively small size, the biggest distance that a prototype needs to be manually

moved should not take more than 10 minutes (600 seconds).

5. Add data and timelines to the Map

Finally, all those times and data are added to the map. As a result, it is seen that the

total Lead times when testing a prototype is 24.600 seconds and the total processing

time higher than 20.400 seconds. This means, on average a prototype should spend

at least a total of 45.000 seconds (12,5 hours) since it arrives in the facilities till it is

stored or delivered. On average, as well, for short tests, the lead times and the

processing times are very similar. However, the longer the test is, the longer the

processing time takes, and the bigger is the difference with the lead times.

To sum up, following those steps has made it possible to create the Ideal Value Stream

Mapping, where all the processes work as planned and there are no downtimes. However, the

current Real Value Stream Mapping of the company differs from the ideal situation. Once the

Ideal situation was created, it was simple to modify it to see where the process is having

inefficiencies, focusing exclusively on the inventory management of the prototypes. On the

Figure 14, it is shown the final Real VSM, having the differences with the Ideal VSM marked

in red.



Figure 13 - Ideal VSM



Figure 14 - Real VSM



Once both VSM have been compared, and just by focusing on the inefficiencies created

by the Inventory control of the prototypes, it is possible to see that they are related with an

increase of the receiving time. The receiving time is defined as the sum of the following:

𝑅𝑒𝑐𝑒𝑖𝑣𝑖𝑛𝑔 𝑡𝑖𝑚𝑒 (𝑠)

= 𝑇𝑖𝑚𝑒 𝑠𝑒𝑎𝑟𝑐ℎ𝑖𝑛𝑔 𝑓𝑜𝑟 𝑡ℎ𝑒 𝑝𝑟𝑜𝑡𝑜𝑦𝑝𝑒

+ 𝑇𝑖𝑚𝑒 𝑚𝑜𝑣𝑖𝑛𝑔 𝑡ℎ𝑒 𝑝𝑟𝑜𝑡𝑜𝑦𝑝𝑒 𝑓𝑟𝑜𝑚 𝑙𝑜𝑐𝑎𝑡𝑖𝑜𝑛 𝐴 𝑡𝑜 𝐵

It has already been explained that the time to move the prototypes is rarely significant

due to the small distances in the facilities. However, the issues start to appear when the time

searching for a prototype is higher than it should be. Optimally, it should not take more than a

couple of minutes to find the latest location of a prototype in the facilities, whilst in real life it

has been experienced that is rather often to spend more than 3 hours in that process. Taking

more time than the necessary on that process can have important consequences, from small

delays in the starting time of a test on its scheduled day, to more relevant postponements. It can

cause tests to be postponed days or even weeks in some occasions, the idleness of the test

benches and, in the worst cases, delays in the delivery of the results of critical tests to the client.

In the real VSM it has been reflected as an example a critical situation where the process

of finding the prototype was taking more than 3 hours for every stage in between processes.

That would mean that the total lead times would increase to 75.600 seconds, which represents

a 307% increase compared with the ideal scenario. However, these difficulties when finding a

prototype do not occur with the same frequency for all the receiving times. They are mainly

detected in the delivery before the first Process, especially if the Supplier is internal and the

prototype had been already been tested and was already allocated inside the testing facilities.

In those situations, the responsible of finding the prototype, the Test Coordinator, or, in some

cases, the Lab Mechanic, is not able to find its physical location, or the prototype has been

misplaced and is not standing in its assigned location.



5.1.2. Muda (waste) identification

A Value Stream Map is especially useful when it comes to waste identification.

According to Lean Thinking, as it has been already explained in the Chapter 3, there are seven

wastes that can be eating up the profits of an organization. To analyse which ones are the ones

affecting the testing processes, it would be necessary to study each one of them keeping the

VSM in mind.

WASTES Influence Level

Over-

production

As previously defined, overproduction is described as the

manufacture of a product before it is needed, which leads to extra

inventory and an increase of storage costs. Since the testing facility

is providing a service and not focused on production, this waste does

not occur.

-

Waiting

This waste happens when some of the processes must be on

hold for a previous transaction. As it has been detected in the current

VSM, this occurs specially when a test is not able to start because

the prototype is not ready or in the wrong position.

Transport

Since the facilities have a small size, the movement or

materials, prototypes or tools does not require a significant amount

of time (typically the longest transportation transaction takes no

more than 10 minutes to be done). Therefore, this is not a waste that

is detected during the analysis.

-

Motion

The insufficient tracking of the prototypes leads to the need

of working hours to search for them. This mainly affects the

responsible workers in the testing facilities. When these situations

occur, they need to go to the different locations where the prototype

might be and check if it is there. It can be concluded that this

unnecessary movement of people is a waste which affects the

facilities.



Over

processing

In the testing facilities there are situations where some

processes are repeated for different reasons. As an example,

sometimes when a prototype arrives in the company is driven

through a quality test that had already been made in the supplier

facilities. This leads to an increase of the lead times, which causes,

as a result, an increment of the waiting time and, in some cases, even

to the postponement of tests.

Inventory

This waste is detected when quantities of different products

(such as raw materials, work in process or finished goods), exceed

the needs of the company. This is especially problematic when the

company has very tight space limitations, since it will increase the

storage costs. Due to the enough storing space in the facilities and

the moderate amount of testing prototypes, this waste does not have

enough influence. The inventory levels can just become an issue for

the tested prototypes that have to be stored in the Validation

Warehouse for long term.

Defects

The main goal of the whole testing Laboratory is to detect

defects on the prototypes. During the testing process there are no

defects being made but detected. Since it is also not focused on a

production process, this waste is not affecting the company.

-

Table 1 - Seven wastes of the testing facilities

To sum up, after analysing the wastes in the facilities in Table 1, there have been

detected three mayor ones: waiting, motion and, with lower impact but still representative,

over processing. The biggest problem these wastes can cause is the postponement of the

starting time of a test, which leads to the idleness of that test bench and delays in sending the

requested information to the customer.



5.1.3. Root cause analysis

The wastes studied previously occur due to two mayor problems of the testing facilities:

• Difficulties when finding a prototype (poor tracking of the prototypes)

• Repetition of processes such as quality processes

In order to obtain a better understanding of the reasons why these issues occur is

necessary to use the Lean tool Root-Cause analysis. It has been decided to use the Fishbone

Diagram or Ishikawa Diagram to do so.

For the first problem, poor tracking of prototypes, there have been detected 7 different

factors: Process, Information, Methodology, Supplier, Man or mind power, Management and

Physical evidences. In the diagram shown in the Figure 15 is possible to see in detail the

underlying causes related with the mentioned factors. By analysing the diagram, it is possible

to investigate the most likely causes further and detect which ones are contributing to the

problem.

Therefore, from the information shown in the diagram, it is easy to detect correlations

between some of the causes. For instance, the employee’s mistakes can be easily linked with

the fact that there is poor access to the information related with the prototypes status, as well as

there is a lack of a uniform system with standard information about their position. That poorness

in the information system is related with the lack of coordination mechanisms or location

procedures from the management department, since they focus their efforts on improving other

processes which they considered had higher importance.

When it comes to supplier mistakes, since the company cannot control external

processes, it is hard to find a solution for that. However, it has been experienced that those

mistakes do not occur often.

For the second problem, the repetition of processes, there have been distinguished 5

different factors, as shown in detail in the Figure 16. These factors are: Method, Information as

part of the Materials used, Man or Mind power, Management department and Physical

evidences.

The causes that occur with the highest frequency are the ones related with the

Information system and the communication issues. As observed for the problem previously

analysed, ‘difficulties when finding a prototype’, it is also common that the information related

with the status and history of tests a prototype has done is not centralized in a common system.

There is also a lack of standard procedures to log that information properly.



Figure 15 - Tracking of prototypes: Fishbone Diagram



Figure 16 - Over processing: Fishbone diagram



5.2. Design of the solution

Once the different wastes have been identified and studied, the scope of this section is

to evaluate different solutions to eliminate or minimize their influence. As explained in the

previous section, the identified wastes are Waiting, Motion and Over processing. Those

wastes cause delays, misuse of the work force and have important economic impacts which will

be analysed further in detail.

As complementary solutions there will be two additional suggestions, based on the

combination of Lean and Six Sigma tools: the Integration of the internal systems in the Testing

Facilities and a Partial automatization and improvement of the prototype’s tracking. For optimal

results, those two solutions should be used simultaneously. A detailed definition and

explanation of both will be done in the last point of this chapter.

5.2.1. PDCA approach

Before evaluating the different wastes and their possible solutions in detail, it is

necessary to mention that any improvement should be implemented following the PDCA

methodology, schematically shown on the Figure 17.

Figure 17 - PDCA approach

PLANUnderstand and

identify the problems

DO

Gather data and test potential

solutions

CHECK

Analyze the results

ACT

Implement the solution



5.2.2. Waste 1: waiting

Due to the poor tracking of the prototypes, as previously explained, it is often to perceive

waiting times along the process. If those waiting times are spread across the chain, that can

affect the delivery date of results to the customer, which can have critical consequences with

the clients and the signed projects.

Therefore, it is key to reduce as much as possible this waste. In order to do so, there are

three actions or objectives to pursue [24]:

• Improve the synchronization between the processes

• Increase the reliability of processes

• Reduce downtime by improving the efficiency.

As Lean Tools to decrease waiting are particularly useful: Continuous Flow and

Standardized Work. Let’s try to consider both more exhaustively and recommend ways to

implement them in the organization.

5.2.2.1. Continuous flow

As schematically shown in the Figure 18, continuous flow allows to move a single

prototype through every step of the Testing process instead of grouping different prototypes

into batches. Simply, once you start working on a product, you should keep focused on it until

it is ready to be delivered to the customer. [12]

To be more precise, to achieve Continuous Flow in the testing facilities, it would be

necessary to improve the consistency when testing. It should not be possible to start a new test

if the prototype from previous test is still on the Test Bench and its test results has not been

properly logged and sent yet. This would allow to provide value to the customers with a higher

frequency and to decrease the time they spend on hold to receive their order. For the studied

case, that value would be the Information with the Test Results and the customers, the Test

Requestors, from the Development department.

Figure 18 - Working in batches VS Continuous Flow



5.2.2.2. Standardized work

In the testing facilities, standardized work can be achieved by using the business

philosophy Kaizen.

For instance, to define the best practice in the facilities and decrease the waiting waste,

a possible standard could be to try to achieve a daily percentage of missing and misplaced

prototypes less than 5%. It would be necessary to involve all the workers in contact with the

prototypes and make sure the standard is understood and pursued by all of them. Once that

standard is achieved, it would be necessary to be able to properly maintain it. Afterwards the

last step would be to pursue the improvement of that standard, which could be to achieve less

than 1% of daily prototypes, for example.

It can be concluded that the thinking process for Kaizen, in order to achieve

standardization, consists of 4 steps: Define, Achieve, Maintain and Improve (DAMI) [25].

5.2.3. Waste 2: motion

It has previously defined motion as the unnecessary movement of people. To get rid of

this waste, it is often to take two different actions [24]:

• Decrease travel time between stages or process stations

• Remove excessive or unnecessary machine movements or actions

In the testing facilities, unnecessary motion occurs mainly when a Test coordinator

needs to go through the different storage locations in order to find a prototype. A possible action

to take could be to assign an official area near the Test Benches where to allocate the prototypes

that are scheduled to be tested, and therefore decreasing the travel time between the pickup of

the prototype and its setup on the Test Bench. Moreover, if the prototypes have a better-defined

position in the facilities, it would be possible to remove excessive and unnecessary actions,

since it would decrease the time looking for them, and as a result to mitigate the motion.

There is a Lean tool which is typically applied to improve the physical organization of

a company and workplace efficiency, the Japanese methodology 5S.

5.2.3.1. 5S

Although the organization follows with highly accuracy the 5S methodology, there is

still room for improvement when it comes to the prototypes’ storage. To improve its storage, it

should be necessary to dedicate some workforce to apply the mentioned steps in the following

way:

1. Sort: make a list with all the prototypes stored in the different locations of the

facilities, distinguish between necessary and unnecessary ones, in order to get rid of

what is not needed. This would help to increase the free space in the facilities and to

obtain a better understanding of the status of the items that are currently being stored.



2. Set in order: by following the practice of orderly storage, it would be possible to

efficiently pick up the right item, decreasing waste and lead times, and with easy

access for everyone. It should be necessary to assign a place for all the prototypes

and to keep all of them in their place. This step will be more detailly explained in

5.2.5.2.1.

3. Shine: try to create a clean workplace without dirt, dust or garbage, in order to

identify problems such as leaks, spills, excess, damage… more easily. Since this is

a step already followed in the company, it should be enough to keep the efforts on

maintain the workspace clean as it is.

4. Standardize: this step is based on the setting up of standards for a neat and clean

workplace. To make abnormalities more visible to management, it should be needed

to send alarms through tools such as Kanban boards, for instance. Thanks to that, it

would easier and more automatic to detect when a prototype is not in its assigned

position, or to trigger an alarm some days before the start date of a test if the testing

prototype has not arrived or been found yet.

5. Sustain: finally, the last step is to implement habits and behaviours in order to

maintain the stablished standards over the long term. To do so, it should be necessary

to spread the 5S mentality through all the levels of the company and ensure leader

commitment to establish and maintain responsibilities.

5.2.4. Waste 3: over processing

It has been stated that over processing is the performance of more processing than it is

needed to meet the customer’s requirements. In order to eliminate its influence, some tips could

be the following [24]:

• Clarify customers' standards and expectations ahead of time

• Only perform processes that are necessary to meet these expectations and

standards

• Use appropriate processes (avoid overly complex machinery or processes if

possible)

Since the unnecessary repetitions of processes does not occur with high frequency, it is

not a critical waste. However, to prevent it to happen it should be necessary to improve the

communication throughout departments, and to make sure than even the lower areas know the

client requirements and expectations. Through a system like the one that will be explained in

5.2.5.1, it would be possible to log and check easily the process that have already been done to

a prototype. Having that information clear, it would be rarer to repeat processes unnecessarily.

To decrease over processing, it is typically used the Lean Tool Kaizen.



5.2.4.1. Kaizen

On production companies, it is common to use the Takt Time term (time required for

producing one unit) in order to reduce over production. However, since the Testing facilities

are not focused on production, over processing can be reduced just by properly defining the

work sequence and instigating the use of SOP (Standard Operating Procedures). This would be

defined as the exact sequence of steps taken to complete the work. Therefore, the over

processing waste, as well as the waiting times, will be solved when standardizing the different

operations.

5.2.5. Additional solutions

As mentioned, based on the combination of Lean and Six Sigma tools, there will be

suggested two additional solutions to mitigate the wastes. Those solutions are named as the

Integration of Systems and the Partial Automatization of the facilities, and they are based on

Kaizen philosophy of continuous improvement. In the following two sections they will be

explained further in detail.

5.2.5.1.System Integration

This proposal is based on the centralization of the information from the different

management tools used currently in the facilities to plan tests and log the testing information of

the prototypes. That information would be stored in different databases and displayed in a

Matrix that would work as a Kanban board, pursuing Continuous flow. The goal is to improve

the quality of the information, as well as to achieve higher responsiveness, lower transportation

costs, higher product availability and lower safety inventory.

Through Systems Integration, not only it is possible to complement Lean principles, but

also to encourage the employees to pursue continues improvement in the company, as well as

to minimize or eliminate the waste. [26] It helps to analyse business processes more easily and

to improve employee productivity.

When it comes to Inventory Systems, some of the existing benefits of the System

Integration are the optimization of inventory to meet product availability, the improve of the

inventory visibility and the state of the inventory accuracy.

The different management tools whose information would be centralized are the

following ones:

• Prototype Logged Diary: it is a tool filled in everyday by every Test Engineer.

It is a system used by management to check the performance of the test benches

in the Testing Lab. It has information related with the Test Bench they are

operating, the prototype they are testing and the test which is being performed.

Furthermore, it is also used as a diary to log when a Test Bench is being repaired,

when it is not being used, etc.



• Testing Global Plan: it is a tool which can only be modified by management

and it is used to plan all the incoming tests. The information is divided by Test

Bench and it contains, among other data, the requested starting date of every

future test, as well as the prototype that will be tested. It also saves the estimated

duration of every test.

• Assembly Workshop requests: this system is mainly used by the Test

Engineers and the workers in Assembly to indicate when an assembly or

disassembly work needs to be done to a specific prototype.

In order to integrate their information, it would be necessary to develop an additional

system, that could be named as ‘Prototype status system’. It would work as an Inventory System

and it would use their data as schematically shown in the Figure 19.

Figure 19 - Integration of systems

5.2.5.1.1. System description and definition

The whole goal of the system would be to create the Prototype Status Matrix, whose

general definition is shown in the Figure 20. This Matrix could show the daily status of a

number N of prototypes through a number T of days. Thanks to that information, it would be

possible to obtain valuable quantitative outputs related with how the Inventory management of

the prototypes is working.

Prototype Logged Diary

•Past data by test bench

•Tests performed by every prototype

Testing Global Plan

•Future data by test bench

•Tests that will be performed by every prototype

Assembly Workshop requests

•Current and future requests of assembly/disassembly of prototypes

Prototype status system

• Past and current data by prototype

• Information related with tests performed

• Historical status for every prototype

• Requested location

• System data bases



Figure 20 - Prototype Status Matrix

In order to obtain a better understanding about how Prototype Status Matrix works, it

would be necessary to describe more in detail its structure:

• S ꞓ MN x T: Status of the prototype n at the timeframe t

S is a NxT matrix whose components represent the status of a prototype

in a portion of time. For instance, the element s12 would represent the status of

the prototype 1 in the timeframe 2.

• n = 0, 1, …N: Prototype n, being N total number of prototypes

• t = 0, 1, …T: Timeframe t, being T total number of timeframes

• k ꞓ (1, 4): coding for the status of the proto

To classify the physical status of the prototypes there have been created

4 different categories, as shown in the Figure 21. Those categories are: In

position, Testing, Wrong position and Unknown Position; and are assigned to

every prototype by comparing its requested location in a period t and its

current location in that period. Through this system, it is easy to identify the

number of prototypes that need to be reallocated or found, and to trigger alarms

in that case.

Figure 21 - Status codes for the prototypes



• SkSNn: Sum of all the timeframes at which the prototype n had the status k

• TotalSNn: Total of timeframes with logged status for the prototype n

• PercSkSNn: Percentage that the prototype n was at the status k during its

timeframe

• SkDatet: Sum of all the prototypes that had the status k at the timeframe t

• TotalDate

t: Total of prototypes with logged status at the time t

• PercSkDate

t: Percentage of prototypes with status k at the time t

In the Figure 22, it is possible to see an example of the Prototype Status Matrix, using

daily data from 25 prototypes during the month of May, in a Test Bench in particular. As it is

possible to see in the image, there have been tested 4 different prototypes during that month in

that Test Bench. In total, the Bench has only been idle two days, during the first weekend of the

month, which means a 93,54% of utilization.

∀ 𝑠𝑛𝑡 = 𝑘, 𝑆𝑘𝑆𝑁𝑛 = ∑ 𝑠𝑛𝑡

𝑡=𝑇

𝑡=0

𝑇𝑜𝑡𝑎𝑙𝑆𝑁𝑛 = ∑ 𝑆𝑘𝑆𝑁𝑛

𝑘=4

𝑘=1

𝑃𝑒𝑟𝑐𝑆𝑘𝑆𝑁𝑛 =𝑆𝑘𝑆𝑁𝑛

𝑇𝑜𝑡𝑎𝑙𝑆𝑁𝑛

∀ 𝑠𝑛𝑡 = 𝑘, 𝑆𝑘𝐷𝑎𝑡𝑒𝑡 = ∑ 𝑠𝑛𝑡

𝑛=𝑁

𝑛=0

𝑇𝑜𝑡𝑎𝑙𝐷𝑎𝑡𝑒𝑡 = ∑ 𝑆𝑘𝐷𝑎𝑡𝑒𝑡

𝑘=4

𝑘=1

𝑃𝑒𝑟𝑐𝑆𝑘𝐷𝑎𝑡𝑒𝑡 =𝑆𝑘𝐷𝑎𝑡𝑒

𝑡𝑇𝑜𝑡𝑎𝑙𝐷𝑎𝑡𝑒

𝑡



Figure 22 - Example of a Prototype Status Matrix

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This prototype status matrix should be automatically filled in in a daily basis, by

checking the information of each prototype and comparing it with their requested status, to keep

an accurate track and record of its movements. From a Lean point of view, this matrix would

work as a Kanban board since it would help to manage the work at an organizational level and

access to the state of every prototype at any time.

The information of the Prototype Status Matrix should be stored in a Data Base and it

should be accessible and reachable by the workers in the Lab. That database would be named

as Prototypes Database and it should be aligned with three other databases, as shown in the

Figure 23. These databases would provide information of the different storage locations, the

users and the suppliers, as they will be explained further below.

Figure 23 - Databases of the system

When designing the databases, it was considered that they should store as much

information about the prototypes as possible, to enhance Continuous Flow. Following the

principles of Inventory Systems, the databases should be able to help the system to properly

count, track, record and manage the information of the prototypes and the storage locations.

The Prototypes Database is shown on the Table 2, and it should store information

related with different aspects of each prototype:

• Identification and qualitative information: ID, Serial Number, weight,

dimensions, image, description, category, testing type.

• Record information: tests done, historical data.

• Tracking information: RFID tag id, current location, requested location.

• Management information: registration date, status, last modification date,

responsible coordinator, supplier.



DATABASE DATA DESCRIPTION

PROTOTYPES

PROTOTYPE_ID INT(10000) Prototype Identifier given by the system (AUTO_INCREMENT attribute should be added)

PROTOTYPE_SN VARCHAR(200) Serial Number of the Prototype (for example, '524')

RFID_ID INT(10000) Id of the RFID tag placed on the prototype

CATEGORY VARCHAR(200) Category to which the prototype is linked, normally referring to a system or subsystem

TESTING_TYPE VARCHAR(200) Type of the prototype: Debug, Validation or Teardown

WEIGHT INT(1000) Weight of the prototype in g

DIMENSIONS INT(1000) Dimensions of the prototype in cm

PROTOTYPE_IMAGE VARCHAR(200) Jpeg or png file of a picture of the prototype

PROTOTYPE_DESCRIPTION VARCHAR(1000) Optional description of the prototype

REGISTRATION_DATE DATETIME() Date when the prototype was registered in the system

TESTS_DONE VARCHAR[][] Matrix containing information of the tests done for that prototype

HISTORICAL_DATA INT[]

Array of integers containing the historical daily status information of the prototype since it was registered in the system

CURRENT_LOCATION_ID INT(1000) Last location of the prototype registered by the system

REQUESTED_LOCATION_ID INT(1000) Requested location of the prototype

STATUS VARCHAR(100) Current physical status of the prototype: In position, testing, wrong position, unknown

LAST_MOD_DATE DATETIME() Date of the last modification done to the status of the prototype

COORD_RESPONSIBLE_ID INT(1000) Name of the Test Coordinator who is directly responsible of the prototype

PROTOTYPE_SUPPLIER_ID INT(1000) Name of the supplier in charge of an specific SKU

Table 2 - Prototypes Database



The database of the storage locations is described in the Table 3 and should store

information related with the different storage locations, such as their identificatory and code,

their type, their capacity, description… Since it is linked with the prototypes database, it would

be possible to access information such as the number of prototypes stored in a specific location,

their storage availability, etc.


STORAGE

LOCATIONS

STORAGE_ID INT(1000)

Location Identifier

(AUTO_INCREMENT attribute

should be added)

STORAGE_CODE VARCHAR(200)

Storage code used by the Users to

Identify the locations and place the

elements in position, or search for

the elements

RFID_READER_ID INT(10000)

ID of the Walkthrough RFID tags

reader placed at the entrance of

the storage location

USE_TYPE VARCHAR(30) Picking, reserve, storage…

STORAGE_DESCRIPTION VARCHAR(1000) Optional description of the storage

location

LOCATION_CAPACITY INT(1000) Capacity of the storage location in

square meters

WAREHOUSE_IMAGE VARCHAR(200) Jpeg or png file of a picture of the

storage location

Table 3 - Storage Locations Database

The Users and Suppliers databases are detailed in the Table 4 and 5, respectively. The

Users database should store information related with the employees in the Testing Facilities,

such as their personal details, the code of their personal RFID badge and their position in the

company. This database should be linked with the Test Coordinator defined in the Prototypes

Database for each prototype.




USERS

USER_ID INT(1000) User Identifier (AUTO_INCREMENT attribute should be added)

USER_NAME VARCHAR(200) First name and last name of the user

USER_RFID_ID INT(10000) Id of the personal RFID badge of that user

USER_POSITION VARCHAR(30) Position within the firm: Test lab technician, Test engineer, Team Management…

USER_TFN VARCHAR(20) User's telephone number

USER_EMAIL VARCHAR(250) User's mail address

USER_IMAGE VARCHAR(200) Jpeg or png file of a picture of the user

Table 4 - Users Database

The suppliers’ database is key management-wise, and it should store information related

with the different suppliers, such as their name, company, contact information… This database

should be linked with the prototypes database.


SUPPLIERS

SUPPLIER_ID INT(1000) Supplier Identifier (AUTO_INCREMENT attribute should be added)

SUPPLIER_NAME VARCHAR(100) First name and last name of the supplier

SUPPLIER_COMPANY VARCHAR(200) Company for which the supplier is working

SUPPLIER_TFN VARCHAR(20) Supplier's telephone number

SUPPLIER_EMAIL VARCHAR(250) Supplier's mail address

SUPPLIER_IMAGE VARCHAR(200) Jpeg or png file of a picture of the supplier/logo of his company

Table 5 - Suppliers Database



5.2.5.2.Partial automatization and tracking

In order to effectively implement an Inventory System, one of the most recommended

solutions is to invest in automatization. Through this proposal the goal is to try to eliminate

the risk of human error and increase product visibility. The main applied Lean tools are

continuous flow and 5S.

To increase the traceability of the prototypes and visibility in the Testing Lab through

automatization, it is key to analyse which activities are currently done manually and not

providing any added value. For instance, as it has been stated, there is a huge investment of

time in the search of the prototypes, as well as the recording of their testing results, and they

are not very well-defined procedures. If it would be possible to know at any time the latest

location and status of a prototype, without the need of manually logging that information in the

database, that would solve that issue and reduce the motion, waiting and processing wastes.

In order to do so, it should be necessary to increase the automatization in the Testing

Lab. There should be implemented Radio-frequency identification (RFID) tags in the

prototypes, as well as RFID readers in the doors, to know always when a certain prototype is

entering or exiting a certain area. Also, to decrease the risk of human error, the entrance to some

of the locations should be restricted just for people with the proper permissions. To do so, it

would be necessary to add RFID readers at their entrance, as well as to install electromagnetic

door locks and provide the workers personal RFID badges.

This proposal is needed in combination with the Integration of Systems, since it provides

to the Prototype Status System the Current Location of each one of the prototypes, and

completes the information related with the tests performed, as shown in the Figure 24.

Figure 24 - Combination of proposals


•Past data by test bench

•Tests performed by every prototype

Testing Global Plan

•Future data by test bench

•Tests that will be performed by every prototype

Assembly Workshop requests

•Current and future requests of assembly/disassembly of prototypes

Partial automatization and tracking proposal

•Current location of the prototypes

Prototype status system

•Past and current data by prototype

•Information related with tests performed

•Historical status for every prototype

•Requested location

•System data bases

•Current location



5.2.5.2.1. Improvement of the storage locations

This proposal is only effective with a proper classification and distribution of the storage

locations. To redistribute the storage accuracy, it would be necessary to classify the different

prototypes according to various categories, in the Prototype Status System. Those categories

would be the following:

• Debugging prototypes: the main function of these prototypes is to be used to

try the programmed sequences in the Test Benches and find and resolve defects

or problems, before mounting the final prototype to test. These prototypes are

normally tested more than one time and should be storage in a location nearby

the test benches, to increase accessibility.

• Validation prototypes: these prototypes are highly important for the company

since they are used to validate and approve different quality or functionality

standards of the products. They perform the tests once they have been debugged

and they are typically tested only one time. After the test has been done, they are

stored for one year.

• Teardown prototypes: these types of prototypes are similar to the validation

ones, but once they have performed the test it is not necessary to store them, and

they can be discarded.

Therefore, in the Testing facilities, the storage places should be defined to be able to

keep all the different prototypes in place and classified. Since in the current situation there are

not clearly defined positions, those should be created. Depending on the different types of

prototypes and if they have been tested already or not, there should be the different locations

shown in the Figure 25. Those locations should be used by the Prototypes Status System, based

on the Information from the Testing Global Plan, to determine the current Requested Location

for each prototype and store it in the data base.

Figure 25 - Prototypes default locations depending on type of prototypes

Test OK Test NOK

Debugging Test Unit Test Unit Test Unit -

Validation"To test"

warehouseTest Unit

Validation warehouse as

"PASSED"

Validation warehouse

as "FAILED"

Teardown"To test"

warehouseTest Unit

Before testing TestingType of

prototype

After Testing

Teardown warehouse



Accordingly, by looking at the table, the warehouse should be divided in 6 distinct

locations, which must be perfectly defined and easily differentiated one from the other:

• Testing units: inside the testing units there should only be the debugging

prototypes. For those prototypes which are tested in different test benches, there

should be a debugging warehouse close by to those test units and easily

accessible for the mechanics who are responsible for mounting and dismounting

the products.

• “To test” warehouse: it should have a destined location for the validation

prototypes and another one for the teardown ones. There could be an area at the

entrance of every Test Bench where to allocate the next prototype to test by the

Test Coordinator, and therefore make it easier and more accessible for the

Mechanics to know which prototype to mount.

• Validation warehouse: once the validation prototypes have been tested, they

should be stored in the validation warehouse. It would be necessary to assign an

available space for those prototypes which have had a successful outcome from

the test (PASSED), and another one for the ones which have FAILED.

• Teardown warehouse: it should be a small location to store the teardown

prototypes temporarily before they are shipped out from the company. These

prototypes should not occupy an area with big movement of people and there

should be stablished time intervals to review which prototypes need to get out

of the company and the prototype database need to be updated when that occurs.

• Assembly workhouse: when they need to be assembled or disassembled, the

prototypes will be stored in the assembly workhouse. There should be a clear

delimited space for the prototypes that needs work from assembly, and for those

ones which have been already assembled again and need to be picked up.

• Received prototypes: this area should be used to temporarily keep all the new

prototypes that arrive to the company. Every time a prototype arrives, it should

be defined its type and created a new entry in the database. The area must be

allocated right at the entrance, where the prototypes enter in the company.

To keep all the prototypes in order and ensure traceability in the testing facilities, they

should be stored in one of the possible locations. It should be everyone’s responsibility to

reallocate a prototype if it is noticed in a wrong location, as well as the Prototype Status System

will send alarms to the Test Coordinators every time a prototype is misplaced, or its information

has been lost. Therefore, it is important to apply the 5S step “Set in order”, properly [27], as

shown in the Table 6.



SET IN ORDER

RULE

PARTIAL AUTOMATIZATION AND

TRACKING PROPOSAL

Identify an establish a

location for all the

materials needed in the

work and assign fixed

places.

It has already been analysed all the possible storage

locations and determined which prototypes should be

stored in which location, and under what circumstances.

Place heavy products at a

comfortable height to

make it easier to be

picked up.

For the light prototypes that can be lifted by hand, there

are assigned shelves in the different locations. For the

heavier prototypes, they should be placed in the ground,

where it is easy to access to them and pick them up with

a lift or a trolley.

Determine how the things

should be put away and

follow those rules.

It should be responsibility of the Test Coordinators to

warn everybody in contact with the prototypes about its

default locations, and which rules to follow every time a

test is finished, a prototype must be dropped/picked up in

assembly, etc. However, the automatization of the

warehouse, in combination with the Integration of

Systems, would make sure those rules are followed by

sending alarms every time a prototype is misplaced, and

their information do not match.

Table 6 - Set in order step from 5S applied in the Testing facilities

In the Figure 26 is possible to see a proposal of how the Inventory locations in the

Testing Facilities could be allocated. The white space could serve as an extra storage room if

the volume of prototypes increases, and if there is more space needed in the validation

warehouse or the teardown area.



Figure 26 - Proposal of the Inventory Allocations



5.2.5.2.2. RFIDs tags and walkthrough readers

Once it has been defined how to improve the storage locations, there is just one last step

to finish the automatization and tracking proposal definition. That step would be to specify

which elements should be added to the testing areas in order to properly track the location of

the prototypes and to improve the transparency and safety of information in the facilities.

Firstly, to track the location of the prototypes it would be necessary to use two key

elements: RFID tags and Walkthrough RFID readers. Radio-Frequency-Identification or RFID

tags are particularly useful to uniquely identify the tagged prototypes, since they use an

electromagnetic field that transmits data from the tag to a reader. Unlike other similar

technologies, such as barcodes, RFID tags do not require that the scanner keeps a line-of-sight

with each code, they only need to be within range of the tag to read it. [28] Walkthrough RFID

readers are scanners which are typically allocated at the entrance of a room and can read any

RFID tag that passes through them. The characteristics of those tags and readers in the testing

facilities are the following:

• RFID tags: there should be physically attached to every prototype as soon as it

enters the company, and they should be able to resist the testing conditions.

Therefore, they should hold temperatures from -40°C to 200°C and should resist

humidity.

• Walkthrough RFID readers: to automatize the process of reading those RFID

tags, and make it faster, there should be allocated one walkthrough RFID reader

at the entrance of every key location in the warehouse. Those locations would

be the mentioned above: Assembly workshop, each one of the Testing Units and

each one of the warehouses.

The information of the RFID tags and the walkthrough readers should be linked with

the Prototype Status System and the Prototypes Database. Every time a new RFID reader is

activated, that should create a new entry of a prototype in the Database, which should be

updated with the location obtained through the Walkthrough readers.

Secondly, to improve the transparency and safety of information in the facilities, and

therefore increase efficiency, it would be necessary to use personal RFID badges and RFID

door readers to enter in some of the locations. Since the Validation warehouse is storing

particularly sensitive information, it should be accessible just by certain employees, such as the

Test Coordinators.



In the Figure 27 is shown again the map of the facilities with the proposed positions for

the RFID Walkthrough Readers and the RFID door reader. It would be allocated one

Walkthrough reader at the entrance of each one of the Test Units (in case of Test Units with

more than one possible entrance, it should be standardized that every time a mechanic

allocate/take out a prototype from a bench he should cross the entrance with the walkthrough

reader). For the teardown warehouse, the only possible entry should also be the one with the

reader, and the validation warehouse would have at the entrance a RFID door reader.

Every time a prototype crosses a RFID Walkthrough Reader, its current location must

be updated in the database by using the ID of the reader and the previous location registered in

the system. For instance, if the latest location of a prototype was “To Test warehouse” and it

crosses the reader of the cell TU2, the system will update its location to “Test Unit TU2”. When

crossing the reader again to exit the Test Bench, the system should then show “Tested

warehouse”, which shares area with the warehouse “To Test”. By default, the tested prototype

should be kept at the exit of the Test Bench in a specific area till the Test Coordinator picks it

up to move it to its next location.



Figure 27 - Location of the RFID Readers in the Facilities



In total, it would be necessary to install 21 readers at the entrances of key locations and

one reader for the personal cards of the employees in the Validation Warehouse (WH3). That

would be enough to properly track the movements of the prototypes in the Testing facilities.

When a prototype is allocated in the white and grey area between the WH1 and the WH3, the

location in the database would be shown as “In transfer zone”.

In the Figure 28 it is shown a conceptual image of how the RFID Walkthrough Readers

should be installed at the entrance of the Testing Units, as well as the new marked areas that

should be added for temporarily storing the prototypes that have been or are going to be tested.

Figure 28 - Changes at the entrances of the Test Units

This combination of RFID readers and tags is extremely flexible and easy to be modified

in case of company growing, sudden need of extra space and reallocation of areas, among

others.

In the APPENDIX 1: RFID tags and readers, it is offered a proposal of particular RFID

elements that could be used, as well as a brief explanation about what led to their choice and

their unitary price.



5.2.5.3.KPIs

As part of the Control stage from PDCA and DMAIC, it will be necessary to use some

Lean parameters known as KPIs or Key Performance Indicators. They are defined as metrics

which have been designed to track and encourage progress towards critical objectives of the

organization. [13]

There is a wide variety of KPIs, depending on the type of organization, although they

are often divided in two common categories: lagging indicators and leading indicators. [29]

On the one hand, lagging indicators appear after an event has occurred, and they are result-

oriented. They analyse historical data and show a reaction to something that has already

happened in a process. On the other hand, leading indicators give real-time measures of events

happening in the moment. They track right at the process and give predictive factors before an

injury happens.

For the testing facilities, there will be suggested a set of lagging and leading indicators,

using the information obtained through the Prototype Status Matrix and the historical data

gathered.2

5.2.5.3.1.1. Lagging KPIs

The lagging indicators will be obtained, as it is already has been mentioned, using

historical data. More specifically, as shown in the Figure 29, the procurement of the Lagging

KPIs is a process that is done using the historical data from the Prototype Status Matrix. That

information is gathered once when implementing the system, by using the Past data by Test

Bench and prototype that comes from the Prototype Logged Diary and the stored elements in

the different warehouse locations.

From the historical data of the prototypes, it is especially interesting for the testing

facilities, to know how well their inventory control has been working through the time.

2 All the KPIs explained in 0 will be related with just a set of data gathered using daily

information from a sample of 25 prototypes, during the testing period between the 27th of October 2018

and the 31st of May 2019. Therefore, every conclusion made in that chapter, or any result shown will be

only applicable for that sample.



Figure 29 - Procurement process of Lagging KPIs

In the Figure 30 it is possible to see the sampled prototypes and information related with

their location status throughout their lifetime (since they entered the facilities). Some interesting

KPIs that can be extracted from that information are:

• Percentage of prototypes that have been properly stored in the right location

(either ‘In position’ or ‘Testing’) more than 90% of their lifetime = 40%

• Percentage of prototypes that have been stored in a wrong position more than

50% of their lifetime = 36%

• Percentage of prototypes whose position has been unknown more than 20% of

their lifetime = 20%

The task of the testing facility would be to use these parameters as indicators over time

(for example, by checking monthly or weekly) to prove if the performance of the Inventory

tracking is improving. For instance, their goal would be to try to check if the percentage of

prototypes in wrong and unknown position is decreasing, and the percentage of prototypes in

position is increasing.

Figure 30 – Historical results per prototype (%) of the analysed sample

LAGGING KPIs

Prototype Status Matrix (historical data)


Past Data by Test Bench

Stored elements in the

different warehouse locations



In the Figure 31 there are shown the average monthly tendencies in percentage over the

total number of prototypes during the analysed timeframes. When looking at the graph, it is

possible to see that the percentage of testing time has decreased proportionally with the time

since the company has been receiving more prototypes without increasing the number of test

benches. The percentage of prototypes in position has not varied significantly over time (around

~40%), and the prototypes in the wrong position has increased from 25% to 41%. The average

number of prototypes that have been misplaced and whose position is unknown has increased

and decreased in proportion, representing in the last month the 17% of all the prototypes.

Figure 31 – Percentages of monthly historical tendencies of the analysed sample

In the Figure 32 is not only possible to visualize the monthly historical tendencies, but

also how the number of prototypes increases with time, and how they have been managed. It is

possible to see that the number of prototypes in position has been increasing, as well as the ones

in the wrong position. There have been 4 prototypes with an unknown position since January

and on average there are tested less than 2 prototypes per month, for the sample analysed.



Figure 32 - Monthly historical tendencies of the analysed sample

5.2.5.3.1.2. Leading KPIs

The most valuable information from the Matrix is the latest status of the prototypes.

From that information, it is possible to calculate KPIs such as the percentage of prototypes in

position, the percentage of prototypes testing and the percentage of prototypes whose position

is wrong or unknown. For instance, for the day 31/05/2019, there was a 44% of the prototypes

in position, 4% were being tested, 36% were misplaced and the remaining 16% belonged to

prototypes in an unknown position, as shown in the Figure 33.



Figure 33 - Prototype status by 31/05/2019 of the analysed sample

Therefore, a proper way of knowing if the Prototype Status System is working is through

those KPIs. The goal would be to achieve the situation shown in the Figure 34, where it has

been possible to reallocate all the misplaced prototypes, and the missing ones have been found

and put in their correct position. The number of prototypes in position would increase in a

109%, for the analysed sample.

Figure 34 - Improvements in the prototypes’ status for the analysed sample

The process of obtaining the status of the prototypes and, therefore, the Leading KPIs,

is shown in the Figure 35. To know the status of a prototype for a certain date, it is necessary

to compare its requested location with its current location.



Its requested location will be normally given by the information from the Testing

Global Plan, except for those cases when an Assembly Work is required. When there is no

information provided in any of those platforms for a prototype, its requested location should

match with its default location. That location is given by the type of the prototype and the

number of tests done, as it will be further explained in the Figure 25.

Its current location will be obtained as it is explained in 5.2.5.2.2.

Figure 35 - Procurement process of Leading KPIs

One important functionality of the Prototype Status System, related with Kanban boards,

would be the daily check-ups and reminders. To keep the high quality of the system and the

organization, the system would check every day the location of each prototype, it would

compare it with the requested location and would send actions to the Test Coordinators. For the

misplaced prototypes, it would remind them to move them, as well as for the unknown, to

dedicate some workforce to search for them. For instance, in the Table 7 is possible to see the

status for the analysed prototypes, as well as the required actions to take towards them, for the

31st of May 2019.

LEADING KPIs

Prototype Status Matrix (current daily

data)STATUS

Current location

RFID tags information

Previous current location

Requested location

1°. Assembly Workshop

Request

2°. Global Plan

3°. Default location

Prototype type

Number of tests done



ID

31

/05

/19

STATUS BY 31/05/2019

Necessary actions Required

Location Current Location

1 1 VW#2A.3 VW#2A.3 2 3 VW#3B.5 TB#15 Move! 3 1 TB#15 TB#15

4 1 VW#2C.8 TB#15

5 4 ?? ?? Find! 6 3 VW#5A.11 TB#15 Move! 7 1 TB#15 TB#15

8 4 ?? ?? Find! 9 1 VW#2A.4 VW#2A.4

10 4 ?? ?? Find! 11 1 TB#15 TB#15

12 4 ?? ?? Find! 13 3 VW#6B.1 TB#15 Move! 14 3 VW#2C.3 TB#15 Move! 15 1 VW#1A.10 VW#1A.10

16 3 VW#2D.3 TB#15 Move! 17 3 VW#10A.5 TB#15 Move! 18 1 VW#8A.2 VW#8A.2

19 1 VW#2B.1 VW#2B.1

20 3 VW#2A.4 TB#15 Move! 21 1 VW#1D.5 VW#1D.5

22 1 TB#15 TB#15

23 3 VW#5C.3 TB#15 Move! 24 3 VW#2A.1 TB#15 Move! 25 2 TB#15 TB#15

Table 7 - Prototypes by 31/05/2019: Status and actions to take.



5.2.5.4.Steps for their implementation

Once both solutions have been properly defined, one of the lasts but most important

steps is to determine the different stages that should be followed to implement them and analyse

the estimated investment of time that should be made.

STAGE DEFINITION ESTIMATED

TIME

1 Analyse the

organization of

the workplace

Obtain the location of all the prototypes currently

stored in the testing facilities, by following 5S ‘sort’

rules. Make a list with their location and their type

(validation, debug or teardown).

2 days

2 Procurement of

the historical

results

Gather all the historical data from the prototypes

that comes from the Prototype Logged Diary, as it

was explained on the Figure 29. Once that

information has been obtained, and with the

prototypes’ location obtained in the Stage 1, it

would be possible to create a Prototype Status

Matrix and afterwards calculate the Lagging KPIs.

Those KPIs would provide an approximate idea

about how the system has been working in the past

and they would be used as first standard to improve

the storing processes in the facilities. Those results

could be logged in Microsoft Excel, using the Figure

22 as a reference.

7 days

3 Obtention of

the status of the

prototypes

Follow the steps explained in the Figure 35 to obtain

the current status of the prototypes and calculate

the Leading KPIs. To automatize this process, it can

be used Visual Basic as programming language, since

it is compatible with Microsoft Excel.

7 days



4 Improvement of

the storage’s

location

This step should be as described in 5.2.5.2.1.

Following 5S rules, and using the information about

their status, organize the prototypes and assign a

location to all of them. Discard the ones that are no

longer providing added value to the company.

2 days

5 RFID tags and

readers

implementation

Once having determined the new storage locations

and the prototypes have been reorganized, it is

necessary to do the following steps:

• Installation Walkthrough readers and RFID

door readers

• Assignation of RFID tags to every critical

prototype

• Provide a personalized RFID badge to the

employees in the Testing facilities

20 days

6 Creation of the

data bases

Create and define in an open source Data Base

management system, such as PostgreSQL, the four

different databases shown in the Figure 23.

Complete all of them with the information from the

prototypes, the users and the suppliers.

20 days

7 Creation of the

Prototype

Status System

Include some programming and debugging time to

make sure the information of all the systems is

correlated.

10 days

8 Program daily

check-ups

Repeat the Stage 3 in a daily basis (for example, plan

and program daily check-ups at 6am), to obtain the

daily status of the prototypes, update the databases

and the Prototype Status Matrix, and send

reminders to the direct responsible to fix the

location of the misplaced or missing prototypes.

< 5 min

(automatized

process)

Table 8 – Suggested steps for the implementation of the two proposals

To sum up, the implementation of the Prototype Status System and all its features in the

testing facilities would take an estimated time of 68 days. This time could be shortened if some

activities, such as the stage 6 and 7 are started while doing other processes. Afterwards, there

would only be needed less than 5 minutes every day to automatically check the status of all the

prototypes and easily fix any misplacement or issue in the warehouses. The higher the volume

of prototypes in the facilities, the more useful the system will be.



5.2.5.5. Economic feasibility

The determination of the economic feasibility of the presented endeavour is a key last

step to estimate whether it will be profitable for the company. This study analyses the data and

provides a cost outlook for the business project.

To analyse the economic feasibility of the Prototype Status System, it will be composed

a projected 5-year business plan that will compare the costs of implementing the system with

the costs of not having an integrated inventory system and preserving things as they currently

are. The mentioned business plan is presented in the Figure 36 and it compares the total

estimated expenses of the Prototype System with the costs of the current situation.

In order to be able to accomplish this comparison, it has been necessary to make some

hypothesis. For instance, considering that they are tested yearly an average of 85 prototypes per

test bench, that value could provide an approximated number of prototypes currently in the

facilities. Based on the previous yearly growth of the company, it has been estimated a 10%

growth for the incoming years, which would have an influence in the number of Test Benches

and prototypes. In the APPENDIX 2: Estimated parameters for the Economic Feasibility Study,

there are shown the different parameters that have been used when calculating the costs for the

study.

• Total costs of the Prototype Status System

Economically, the Prototype Status System will only need two main investments. The

first one will consist on an initial payment in the first year for the implementation of the whole

system and its elements in the Testing Facilities. This is mentioned in the business plan as

‘Implementation Investment’, and it gives an estimated cost for all the steps explained in

5.2.5.4. Furthermore, it considers the cost of the necessary hardware (RFID tags and readers)

and the salaries of the employees in charge of its setup, such as programmers for the software

and technicians for the hardware installation. The estimated Implementation Investment of the

system would be 58.482,7 €.

Once the whole system has been successfully implemented and debugged, it will be only

needed to do a brief maintenance and control work every year to ensure its functioning. That

work will mainly consist on the registration of the new prototypes in the system, which has

been estimated to take 15 minutes per prototype (considering the assignation of a new RFID

tag and the creation of a new entry in the Prototypes database). The responsible employees for

that task could be the Test Coordinators, since they oversee the status and traceability of the

prototypes and the tests they perform. The costs of this control and maintenance will increase

as the number of prototypes do, being 5.534 € for the Year 1 and 8.102 € for the Year 5.



• Total costs of the current situation

To take an economic outlook over the current situation, it is necessary to consider the

inventory costs in the facilities. These costs are shared by every storage location and, as

explained in the Chapter 3, there are split in three different expenses: ordering costs, holding

costs and shortage costs.

The implementation of the Prototype System would improve the traceability of the

prototypes, which is directly linked with a decrease in shortage costs. Since it would not affect

the annual purchases, the ordering costs would not be altered and the difference in holding costs

would be almost insignificant, considering that the rent and depreciation are the same for all

the company storage units and there is currently enough space to store all the prototypes.

However, due to the growing tendency of the company, the holding costs could gain importance

soon and the available space would be a more critical constrain.

Therefore, for the current analysis there have been only studied the most significant

inventory costs, which are the shortage costs.

To measure them, it has been acknowledged that every day there is at least 1 hour spent

on looking for a prototype. That means, every day at least one employee (normally one of the

test mechanics), is spending one-hour time on that task, and there is at least one test bench

whose activities are on hold due to the absence of the testing prototype. This provides the most

common and less aggressive scenario for the analysis.

Accordingly, the total costs of the current situation will be the sum of the total shortage

costs and its related salary costs. On average, every test bench cost 2.500€ a day, that leads to

104,17€ per hour, which repeated 20 times per month, provides the value of the yearly shortage

costs. The salary costs are calculated using the test mechanics’ payroll. This gives a minimum

value of 34.600 € that are yearly spent due to the poor traceability of the prototypes.



Figure 36 – Economic feasibility study

BU

SINESS P

LAN

Year 0Year 1

Year 2Year 3

Year 4Year 5

Nu

mb

er of Test B

ench

es16

1718

1919

20

Nu

mb

er of Pro

totyp

es1357

14251496

15711649

1732

Average am

mo

un

t of n

ew p

roto

types

-68

7175

7982

RFID

tags2,700.03

€ 135.00

€ 141.75

€ 148.84

€ 156.28

€ 164.10

€

Lamin

ate RFID

tags for th

e emp

loyees’ b

adges

32.67€

--

--

-

Walkth

rou

gh R

FID read

ers35,700.00

€ 1,360.00

€ 1,428.00

€ 1,499.40

€ 1,574.37

€ 1,653.09

€

RFID

reader fo

r the em

plo

yees’ bad

ges and

com

pu

ter ho

st4,050.00

€ -

--

--

Program

min

g of th

e softw

are12,000.00

€ -

--

--

Installatio

n o

f the h

ardw

are4,000.00

€ -

--

--

Imp

lemen

tatio

n In

vestmen

t58,482.70

€ 1,495.00

€ 1,569.75

€ 1,648.24

€ 1,730.65

€ 1,817.18

€

Co

ntro

l and

main

ten

ance

-€

1,272.00€

1,335.60€

1,402.38€

1,472.50€

1,546.12€

TOTA

L CO

STS PR

OTO

TYPE SYSTEM

58,482.70€

2,767.00€

2,905.35€

3,050.62€

3,203.15€

3,363.31€

Aggregate

cost

58,482.70€

61,249.70€

64,155.06€

67,205.67€

70,408.82€

73,772.13€

Sho

rtage costs

25,000.00€

25,000.00€

25,000.00€

25,000.00€

25,000.00€

25,000.00€

Salary costs

9,600.00€

9,600.00€

9,600.00€

9,600.00€

9,600.00€

9,600.00€

TOTA

L CO

STS CU

RR

ENT SITU

ATIO

N

34,600.00€

34,600.00€

34,600.00€

34,600.00€

34,600.00€

34,600.00€

Aggregate

cost

34,600.00€

69,200.00€

103,800.00€

138,400.00€

173,000.00€

207,600.00€

DIFFER

ENC

E(23,882.70)

€ 7,950.30

€ 39,644.94

€ 71,194.33

€ 102,591.18

€ 133,827.87

€



• Costs comparison

Finally, by comparing both alternatives and calculating the difference between them, it

is possible to detect which one will be more beneficial economically for the company. In the

Figure 37 it is shown how their estimated costs evolve over time. Both show an increasing

tendency, being the current situation significatively faster than the prototype system alternative.

Although the costs during the initial year are higher for the Prototype System proposal

due to its implementation (58.482,7 € versus 34.600 € of the current situation), the costs of the

maintenance and control are noticeably lower and could reduce the company’s costs

significantly from the Year 1 onwards. By implementing the Prototype System, it will be

possible to have saved up to 133.827,87 € by the Year 5.

Figure 37 - Costs comparison between the Prototype System and the Current situation



5.3. Legal, professional and economic impacts

This last part of the chapter is focused on the study of the different impacts that this

project might cause in society. Those impacts will be mainly legal, professional and ethical.

Legally, the impacts of this project are related with the licenses of the computer

programs that have been used. There have been needed open-source programs such as

GanttProject or licensed programs such as Adobe or the Office package from Microsoft.

Professionally, the proposed suggestions to improve the processes in the facilities

would offer several benefits. The existence of a system with instant access to the information

would significantly reduce the motion, decrease the tracking time, increase the knowledge and

improve the communication, etc. Moreover, the safety and security of information would

increase, and the employees could improve their performance, by focusing on tasks with higher

added value for the company.

Economically, the solution offered in this project would suppose a relevant saving in

costs if properly implemented in the company. Those savings would be directly related with the

elimination of wastes and optimization of the processes, and therefore with the increase of the

efficiency of the company and its employees.



Chapter 6.

CONCLUSIONS

6. CONCLUSIONS

Once having finished the results and discussion, it is possible to obtain the conclusions

of this Master Thesis. Those conclusions are divided into general conclusions, specific

conclusions and limitations of the project.

6.1. General conclusions

The main goal of this Master Thesis was to analyse how the application of Lean and Six

Sigma tools could improve the performance of the Testing Facilities in a mechanical company.

In order to do so, it has been carried out a detailed analysis of the activities executed in the

department and the influence that the management of the testing components has in its

performance.

When working in this project it has been possible to acknowledge the importance of

investing in a proper Inventory System, especially in a company where it is so critical to keep

its items accordingly tracked. Moreover, there have been recognized the benefits of applying

Lean and Six Sigma methodologies. It has been discovered that, with the current situation, the

performance in the Lab is far from optimal. There has been detected three wastes that cause

noticeable economic impacts, as well as an inadequate use of the workforce and the inventory.

By implementing the solutions suggested in this Master thesis, related with the enhancement of

the management of the prototypes, that situation could be improved. Besides the economic

benefits, the company could take strategic advantages from performing a better tracking of the

prototypes, as well as the eight waste would be decreased by preventing the employees from

losing time on searching tasks.

From a personal point of view, working on this Master thesis in order to finish the

Master of Engineering in Industrial Technologies has been a challenging but enriching

experience. It has been possible to acquire valuable technical knowledge as well as there have

been improved professional skills such as self-work and management, preparation of reports

and meetings’ performance and arrangement.

CONCLUSSIONS


6.2. Specific conclusions

Once the project has been done, it is possible to realise that all the specific objectives

detailed in the chapter 2.2, has been achieved:

1. It has been defined, measured and analysed the current processes in the Testing

facilities by using Lean tools such as Value Stream Mapping.

2. There have been identified the different wastes related with the prototypes and

existing in the facilities, which are waiting, motion and processing. Also, it has been

carried out a root cause analysis for those wastes.

3. It has been studied the different solutions to mitigate the effect of each one of the

wastes, by applying Lean tools such as PDCA, 5S, Kaizen, Continuous Flow and

Standardized job.

4. There have been proposed alternative solutions based on Lean and Six Sigma

methods, such as system integration and a partial automatization of the facilities. In

the Table 9 is possible to see how each one of the proposals would contribute to the

wastes’ elimination.

Table 9 - Proposals overview and wastes

5. It has been defined and described the Integration of systems proposal and suggest

possible KPIs to analyse its performance.

a. This proposal would be based on virtual aggregation by combining the

information of the existing Information systems to obtain the status of the

prototypes.

b. It has been described the “status of a prototype” as its geographical

information in a specific moment.

Integration of

systems

Partial

automatization

and improvement

of inventory

tracking

Synchronize processes as much as possible ✔

Increase reliability of processes ✔ ✔

Reduce down time by improving efficiency ✔

Decrease travel time between stages or process stations ✔

Remove excessive or unnecessary machine movements/actions ✔ ✔

Clarify customers' standards and expectations ahead of time ✔

Only perform processes necessary to meet these standards and

expectations✔ ✔

Use appropriate processes (avoid overly complex machinery or

processes if possible) ✔

Waiting

Motion

Processing

Proposals

Wastes Solutions



c. It has been defined the Prototypes Status Matrix, which would provide an

overview of the current situation, working as a virtual Kanban board.

d. To pursue continuous flow, there has been defined 4 databases: prototypes,

storage, users and suppliers, whose information would improve the

performance of the Inventory System.

e. There have been suggested lagging and leading indicators as possible KPIs,

as a Control step of the PDCA and DMAIC approach.

6. It has been defined the Partial automatization and tracking proposal and its

needed elements.

a. This proposal complements the Integration of Systems by providing the

current status of each prototype.

b. It has been carried out an analysis to improve the storage locations based on

the type of prototypes and following 5S rules.

c. There have been suggested RFID readers and Walkthrough readers as

possible elements to improve the tracking of the prototypes and contribute

to continuous flow.

7. There have been defined 8 necessary steps to successfully implement both

proposals.

8. It has been analysed the economic feasibility of the proposals. There have been

perceived the clear economic benefits that its implementation would have in the

Testing facilities.

9. Moreover, it has been followed the DMAIC methodology [30] from Six Sigma to

identify and search for the solution.

a. Define: it has been identified the problem, as well as its boundaries and goals

through the initial studies and observations. It has been detected that the

company’s inventory system is not properly developed in its testing

facilities.

b. Measure: the VSM has been used to obtain a global view and measurements

of the facilities, as well as to determine the “current state” of the project.

c. Analyse: the data has been interpreted to identify key causes and process

determinants through Muda identification and Root cause analysis.

d. Improve: in order to optimize the performance of the processes in the

facilities, there has been suggested several solutions for each waste by using

Lean tools, as well as two additional proposals.

e. Control: there has been defined KPIs to be able to check whether the gains

are sustained.

CONCLUSSIONS


6.3. Limitations

During the project there has been faced some limitations, mainly related with the

restrained access to information. Firstly, it is important to mention the confidentiality aspects

that made the gathering of data a difficult task. It has been only possible to access to a limited

amount of information that has been combined with the observations and feedback from the

interviews.

Secondly, some internal difficulties and the lack of standardization and transparency in

processes made it arduous to access to some of the previous and current data. Some Lean

methods were then not possible to be applicable, such as Spaghetti diagrams.

Finally, the time limitations conditioned the size of the sample taken for the discussion.

However, although a bigger sample could affect the results, the followed procedure in order to

obtain them would be the same.



Chapter 7.

FUTURE WORK

7. FUTURE WORK

Throughout this thesis there have been found several subjects which could be interesting

for further research and work.

1. Increase the sampling to obtain the real data in the facilities: due to timing

limitations, the project has been done by using a sample of 25 prototypes, during the

testing period between the 27th of October 2018 and the 31st of May 2019. As a

future action, it should be necessary to include the data from all the prototypes

currently stored and used in the facilities.

2. Implementation of the suggested proposals: as a future work, the next step could

be to implement the theoretical suggestions of this thesis in the facilities. The stages

explained in 5.2.5.4 could be used as a reference.

3. Performance tests: in order to check the effectiveness of the proposals, there could

be performed different trial attempts till reaching validation. It could be followed

the PDCA cycle to perform this future work.

4. Resistance to changes: a Lean and Six Sigma application requires the involvement

of the workers and employees. One of the hardest but necessary tasks if the proposals

are implemented, would be to gradually change their mindset. That change should

be gradual and would cover the acceptance of the standards, the learning of the new

procedures and the change of methodologies. Moreover, it would be also an

interesting area of study to explore the enthusiasm and willingness for the employees

to implement Lean throughout the facilities.

5. Programming language: for the current data gathered, Microsoft Excel is enough

to plot and analyse the information logged of the prototypes in the Prototype Status

Matrix. However, for future analysis of the KPIs and once the databases increase

their volume, it would be necessary to use more powerful programming languages

of analysing data, such as Python or Visual Basic, for instance.

6. User interface: for future data visualization and specific searches, it would be

beneficial to invest in a proper user interface for the Prototype Status System. Thus,

it could be possible to show the results in a user-friendly way and ease the

management tasks.

FUTURE WORK




Chapter 8.

TEMPORAL PLANNING AND

PROJECT BUDGET

8. TEMPORAL PLANNING AND PROJECT BUDGET

The main goal of this chapter is to show the temporal planning of the project, its work

breakdown structure and its project budget.

8.1. Temporal Planning

The project started on November 2018, but it was not till February 2019 that it started

to take its final shape. This fact is due to a pair of meetings that occurred internally with one of

the Planning responsible employees in the Testing facilities. After the first meeting, which took

place in November of 2018, it was defined the project scope of the thesis and which researches

to do during the incoming months. However, in February it was planned another meeting to

solve some questions and issues and during that encounter it was agreed to redefine the project

scope. That led to a new change of approach and perspective that entailed a new project

structure.

There are two different stages that split the performance of the project. The first stage,

based on personal preparation and study of the theoretical requirements of the project, lasted

till May of 2019. The stage of the results and discussion of the project occurred between May

and September of 2019. In total, the whole duration of the project has been 11 months, and in

the Figure 38 is possible to see the distribution of worked hours per month.

There have been considered the hours dedicated to the preparation and development of

the solution, as well as the extra hours that were needed to prepare the report. To sum up, there

have been invested 377 hours on this Master thesis.

TEMPORAL PLANNING AND PROJECT BUDGET


Figure 38 - Monthly number of hours worked in the project

In the Figure 39 is shown the Gantt Chart with the temporal planning of the project,

divided by tasks. The chart has been made by using the software “GanttProject”, and it offers a

detailed view of the start and end date of the tasks done, as well as the order that has been

followed to accomplish them.

A representation of the Work Breakdown Structure can be seen in the chapter 8.2, in

the Figure 40, which provides a view of all the stages done in other to perform this project.

They are linked with the tasks represented in the Gantt Chart.



Figure 39 - Gantt chart of the project



8.2. Work Breakdown Structure

Figure 40 - Work Breakdown Structure of the project

Mas

ter

Thes

is

PROJECT MANAGEMENT

Planning

Project scope

Redefining project scope

Project Structure

Control and monitoring

Deliverables

Meetings

PREVIOUS STUDIES

State of the art

Inventory Management Systems

Lean Thinking and Six Sigma

Data Gathering

Historical data

Interviews and researches

DEVELOPMENT

Data analysis

Application of theoretical background

Wastes Identification

Application of Lean tools to solve wastes

Definition of proposed solutions

DOCUMENTATION

Report

Review



8.3. Project Budget

The aim of this chapter is to provide an economic study of this Master thesis. That study

would provide an estimated cost of the project based on two concepts: the workforce and the

computer material.

The workforce was one junior engineer and one senior engineer expert in management

of warehouses and Lean techniques. Estimating an hourly salary of 25 € for the junior engineer

and considering there were needed 461 hours to do the project, his total cost would be 11.525

€. The senior engineer should receive an estimated wage of 100 € per hour. Considering

meetings and reviewing time, he needed to invest 16 hours in the project, what makes a total of

1.600 €. Thus, the total cost of the workforce during the 11 months of the Master thesis would

be 13.125 €.

The computer material considers the hardware and software that was needed for the

project. As hardware, it has been used a Laptop Lenovo IdeaPad 320, whose cost is 699,95 €

[31] and a HP USB Optical Scroll Mouse of 10,99 € [32]. The total cost of the devices is 710,94

€ and, assuming a 5 years amortization, during 11 months of work on the project, the estimated

cost is 130,34 €.

As software, it has been used open-source programs as much as possible, except for

Adobe Photoshop, whose price is 24,19 € per month [33], being the total cost 266,09 €, during

11 months of work. It has been also needed the Microsoft Office package, which costs 9,99 €

per month [34], being 109,89 € for the total project.

In the Table 10 there is a summary of the costs of the project, being 13.631,32 € the total

estimated investment that would be needed to perform this Master thesis.

Table 10 - Total cost of the project considering the requirements for the workforce and material

11,525.00 €

1,600.00 €

130.34 €

Adobe 109.89 €

Office 266.09 €

13,631.32 €TOTAL

Computer material

WorkforceJunior Engineer

Senior Engineer expert

Hardware

Software licenses



9. REFERENCES

[

1] Melanie, Unleashed, 26 May 2017.

https://www.unleashedsoftware.com/blog/mportance-taking-inventory-control.

[

2] H. Averkamp, Accounting Coach,

https://www.accountingcoach.com/blog/calculate-inventory-carrying-cost.

[

3] Melanie, Inventory costs: ordering, carrying and shortage, UNLEASHED,

https://www.unleashedsoftware.com/blog/inventory-ordering-carrying-shortage.

[

4] A. HAYES, Investopedia,

https://www.investopedia.com/terms/i/inventory-management.asp.

[

5] K. Hamlett, About Inventory Systems,

https://smallbusiness.chron.com/inventory-systems-2232.html.

[

6] Lean Production, Vorne,

https://www.Leanproduction.com/.

[

7] Lean Enterprise Institute: A brief story of Lean,

https://www.Lean.org/WhatsLean/History.cfm.

[

8] Seven Deadly Wastes, Lean Production,

https://www.Leanproduction.com/intro-to-Lean.html.

[

9] K. Ishikawa, Introduction to Quality Control, 1990.

[

10] M. C. Team, MindTools: Cause and Effect Analysis,

https://www.mindtools.com/pages/article/newTMC_03.htm.

[

11] M. T. C. Team, Plan-Do-Check-Act (PDCA), MindTools,

https://www.mindtools.com/pages/article/newPPM_89.htm.

[

12] kanbanize, Continuous Flow,

https://kanbanize.com/continuous-flow/.

[

13] Vorne, The Essence of Lean: SEVEN DEADLY WASTES,

https://www.Leanproduction.com/intro-to-Lean.html.

[

14] J. S. a. T. Narusawa, Kaizen Express.

[

15] BPI, Lean Manufacturing and Six Sigma Definitions,

http://Leansixsigmadefinition.com/glossary/5s/.

[

16] Lean Enterprise Institute,

https://www.Lean.org/Workshops/WorkshopDescription.cfm?WorkshopId=20.

REFERENCES


[

17] D. RADIGAN, Kanban: How the kanban methodology applies to software

development,

https://www.atlassian.com/agile/kanban.

[

18] C. Intrieri, Lean Inventory: Using Lean Initiatives To Manage Inventory,

Cerasis,

https://cerasis.com/Lean-inventory/.

[

19] iSixSigma-Editorial, iSixSigma,

https://www.isixsigma.com/new-to-six-sigma/what-six-sigma/.

[

20] D. P. K. K. P. M. Sokovic, Quality Improvement Methodologies – PDCA

Cycle, RADAR Matrix, DMAIC and DFSS, Journal of Achievement in Materials and

Manufacturing Engineering, vol. 43, no. 1, 2010.

[

21] THE DEFINE, MEASURE, ANALYZE, IMPROVE, CONTROL (DMAIC)

PROCESS, ASQ,

https://asq.org/quality-resources/dmaic.

[

22] T. R. Pressly, The breakthrough management strategy revolutionizing in the

Top's world, Ohio CPA journal, pp. 69-70, 2001.

[

23] S. PEARSON, Tallyfy,

https://tallyfy.com/value-stream-mapping/.

[

24] M.-K. Hassiotis, Infographic: Eliminating the 7 Wastes of Lean

Manufacturing (Muda), 24 March 2016.

https://news.ewmfg.com/blog/infographic-eliminating-the-7-wastes-of-Lean-

manufacturing-muda.

[

25] T. Richardson, Standardized Work for Kaizen: Define, Achieve, Maintain,

Improve, THE LEAN POST, 7 January 2014.

https://www.Lean.org/LeanPost/Posting.cfm?LeanPostId=124.

[

26] S. A. Campion, System Integration Meets Lean Manufacturing,

https://www.qualitymag.com/articles/93746-system-integration-meets-Lean-

manufacturing.

[

27] E. R. &. T. Richardson, The Value of Key Performance Indicators in a Lean

Transformation, THE LEAN POST, 2016.

[

28] Lean Manufacturing and Six Sigma Definitions,

http://Leansixsigmadefinition.com/glossary/5s/.

[

29] GopherWerx, RFID vs. Barcode – What’s the Difference?,

http://gopherwerx.com/rfid-vs-barcode-difference/.



[

30] E. CLOWER, Applying DMAIC to Inventory Problems: Fixing an inventory

disaster, QualityDigest,

https://www.qualitydigest.com/inside/six-sigma-article/applying-dmaic-

inventory-problems-031210.html.

[

31] KiesProduct,

https://www.kiesproduct.nl/q/Lenovo-IdeaPad-

320?msclkid=6edfe4a6e886154fd12bb9cbd70c81cc&utm_source=bing&utm_medium=

cpc&utm_campaign=Lenovo&utm_term=Lenovo%20IdeaPad%20320&utm_content=L

enovo%20IdeaPad.

[

32] Dodax,

https://www.dodax.nl/nl-

nl/dp/1U2FG0K9ILE/?utm_source=httpwwwprijswatchernl&utm_medium=zanox&utm

_content=products&utm_campaign=webshop-

promo&awc=8248_1567441454_c61f4bad935fd4b65c547ece9ae9092f.

[

33] Adobe,

https://commerce.adobe.com/checkout/email/?items%5B0%5D%5Bid%5D=30404A88

D89A328584307175B8B27616&items%5B0%5D%5Bq%5D=1&cli=adobe_com&lang

=nl&co=BE&promoid=&sdid=&trackingid=&mv=&rUrl=.

[

34] Office Products,

https://products.office.com/en-us/buy/office.

[

35] UHF 915 MHZ FR4 HIGH TEMPERATURE RFID TAGS,

https://www.rfidinc.com/uhf-915-mhz-fr4-high-temperature-rfid-tags.

[

36] UHF 915 MHZ PVC LAMINATE RFID TAGS,

https://www.rfidinc.com/uhf-915-mhz-pvc-laminate-rfid-tags.

[

37] HopeLand,

https://www.hopelandrfid.com/access-control-rfid-tracking-gate-reader-

cl7226d_p21.html.

[

38] Alibaba.com,

https://www.alibaba.com/product-detail/Card-reader-Distance-5m-Hf-

Gate_60780354192.html?spm=a2700.7724857.normalList.262.1b10636aDHua8B.

[

39] Learn Management, Hierarchical Structure,

https://www.learnmanagement2.com/hierarchical%20structure.htm.

[

40] S. Bragg, Shortage costs, AccountingTools,

https://www.accountingtools.com/articles/2017/5/16/shortage-costs.

REFERENCES




10. ABBREVIATIONS AND ACRONYMS

5S Sort, Set in Order, Shine, Standardize, Sustain

DAMI Define, Achieve, Maintain, Improve

DMAIC Define, Measure, Analyse, Improve, Control

EoL End of Line

ETSII Escuela Técnica Superior de Ingenieros Industriales

ID Identificador

KPI Key Performance Indicator

PDCA Plan, Do, Check, Act

RFID Radio-frequency identification

SOP Standard Operating Procedures

UNESCO United Nations Educational, Scientific and Cultural Organization

URL Uniform Resource Locator

VSM Value Stream Mapping

WBS Work breakdown structure

WWW Word Wide Web

LIST OF FIGURES




List of figures

Figure 1 - Structure of the company ......................................................................................... 24

Figure 2 - Structure of the Testing Lab .................................................................................... 25

Figure 3 - Processes in the company ........................................................................................ 26

Figure 4 - Tests requesting process .......................................................................................... 28

Figure 5 - Test readiness requirements .................................................................................... 29

Figure 6 - 2D map of the Testing Facilities ............................................................................. 30

Figure 7 - Optimum batch size in Inventory Control ............................................................... 36

Figure 8 - Basic characteristics of inventory systems .............................................................. 37

Figure 9 - 5S steps .................................................................................................................... 40

Figure 10 - Six Sigma distribution ........................................................................................... 41

Figure 11 - DMAIC Methodology ............................................................................................ 42

Figure 12 - Prototype stakeholders in the Testing Facilities ................................................... 46

Figure 13 - Ideal VSM .............................................................................................................. 49

Figure 14 - Real VSM ............................................................................................................... 50

Figure 15 - Tracking of prototypes: Fishbone Diagram .......................................................... 55

Figure 16 - Over processing: Fishbone diagram ..................................................................... 56

Figure 17 - PDCA approach .................................................................................................... 57

Figure 18 - Working in batches VS Continuous Flow .............................................................. 58

Figure 19 - Integration of systems ............................................................................................ 62

Figure 20 - Prototype Status Matrix ......................................................................................... 63

Figure 21 - Status codes for the prototypes .............................................................................. 63

Figure 22 - Example of a Prototype Status Matrix ................................................................... 65

Figure 23 - Databases of the system ........................................................................................ 66

Figure 24 - Combination of proposals ..................................................................................... 70

Figure 25 - Prototypes default locations depending on type of prototypes .............................. 71

Figure 26 - Proposal of the Inventory Allocations ................................................................... 74

Figure 27 - Location of the RFID Readers in the Facilities ..................................................... 77

Figure 28 - Changes at the entrances of the Test Units ........................................................... 78

Figure 29 - Procurement process of Lagging KPIs .................................................................. 80

Figure 30 – Historical results per prototype (%) ..................................................................... 80

Figure 31 – Percentages of monthly historical tendencies ...................................................... 81

Figure 32 - Monthly historical tendencies................................................................................ 82

Figure 33 - Prototype status by 31/05/2019 ............................................................................. 83

Figure 34 - Improvements in the prototypes’ status ................................................................. 83

Figure 35 - Procurement process of Leading KPIs .................................................................. 84

Figure 36 – Economic feasibility study .................................................................................... 90

Figure 37 - Costs comparison between the Prototype System and the Current situation ........ 91

Figure 38 - Monthly number of hours worked in the project ................................................. 100

Figure 39 - Gantt chart of the project .................................................................................... 101

Figure 40 - Work Breakdown Structure of the project ........................................................... 102

LIST OF FIGURES




List of tables

Table 1 - Seven wastes of the testing facilities ......................................................................... 53

Table 2 - Prototypes Database ................................................................................................. 67

Table 3 - Storage Locations Database ..................................................................................... 68

Table 4 - Users Database ......................................................................................................... 69

Table 5 - Suppliers Database ................................................................................................... 69

Table 6 - Set in order step from 5S applied in the Testing facilities......................................... 73

Table 7 - Prototypes by 31/05/2019: Status and actions to take. ............................................. 85

Table 8 – Suggested steps for the implementation of the two proposals .................................. 87

Table 9 - Proposals overview and wastes................................................................................. 94

Table 10 - Total cost of the project considering the requirements for the workforce and material

............................................................................................................................................................. 103

Table 11 - Possible RFID tags and readers ........................................................................... 115

Table 12 - Estimated parameters used in the Economic Feasibility study ............................. 117

Table 13 - Estimated salaries used in the Economic Feasibility Study .................................. 117



APPENDIX 1: RFID tags and readers

Image Name Reference Comments

Unitary

price

RFID tags for

the prototypes

UHF 915 MHZ

fr4 high

temperature

RFID tags [26]

Able to hold extreme

temperatures up to

200°C

€ 1.99

Laminate

RFID tags for

the

employees’

badges

UHF 915 MHZ

pvc laminate

RFID tags [27]

Affordable and

frequency within the

range

€ 0.99

Walkthrough

RFID Reader

Access Control

RFID Tracking

Gate Reader

CL7226D [28]

Suitable to read the

RFID tags for the

following reasons:

-Supports 860 to

960MHz UHF RFID

Cards

-Working width up to 3

meters

€ 1700

RFID reader

for the

employees’

badges

Card-reader

Distance 5m Hf

Gate Rfid Long

Range Reader

with Sdk [29]

Suitable cause it can

detect the frequency

range: 902~928MHZ

(FCC)

€ 160

Table 11 - Possible RFID tags and readers

APPENDIX




APPENDIX 2: Estimated parameters for the Economic

Feasibility Study

Table 12 - Estimated parameters used in the Economic Feasibility study

Table 13 - Estimated salaries used in the Economic Feasibility Study

ESTIMATED PARAMATERS

RFID tags for the prototypes 1.99 €/unit

Laminate RFID tags for the employees’ badges 0.99 €/unit

Total number of employees in the Testing Facilities 33

Walkthrough RFID Reader 1700.00 €/unit

Total number of walkthrough RFID Readers needed in Year 0 21

RFID reader for the employees’ badges and computer host 4050.00 €

Annual growth 10%

Average number of prototypes tested in a test bench per year 85

Average time to register a new prototype in the system 15 min

Average hour cost of a Test Bench 104.17 €/hour

Average number of working days per month 20

ESTIMATED SALARIES (€/hour)

Programmer 100€

Technician 40€

Test Coordinator 75€

APPENDIX




APPENDIX 3: Interview guide

Most interactions with the employees in the Testing facilities were through casual

observations and non-interfering queries during the workday. The following questions were

defined as necessary to obtain a more precise idea about the performance of the Lab.

• How is the planning done on a daily basis?

• Who is the people responsible of keeping track of all the prototypes in the lab

nowadays and how are they kept track?

• Is there any existing inventory system for the prototypes in the lab? If so, which

one and how does it work?

• Which type of prototypes are stored?

• How many new prototypes arrive every month/year for testing?

• How often does a prototype get lost? Which are the issues faced when trying to

find it?

• Which the protocol when looking for a prototype?

• Who is working in the lab and has access to the stored mechanical components

(stakeholders)?

• Is there any map of the warehouse and the distinct storage locations? How are

they stored? Is there already a protocol to follow when storing the different

elements? (Stored according to categories, type of products, etc.)

• Label data system: are there different types of labels depending on the elements

that they stored?

• Which are the daily costs of the test benches?

efficiency and effectiveness analysis of the …

Documents