jit,waiting line, 5 s,kaizen qualiyty mgmt techniques

7/28/2019 Jit,Waiting Line, 5 s,Kaizen Qualiyty Mgmt Techniques

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Just In Time:

A philosophy of manufacturing based on planned elimination of waste and

continuous improvement of productivity

Just-in-time (JIT) is an inventory strategy that strives to improve a business's

return on investment by reducing in-process inventory and associated carrying

costs. The main objective of JIT manufacturing is to reduce manufacturing lead

times. This is primarily achieved by drastic reductions in work-in-process (WIP).

The result is a smooth, uninterrupted flow of small lots of products throughout

production

Just In Time production method is also called the Toyota Production System. This

system is used for planning and controlling production. To meet JIT objectives, the

process relies on signals or Kanban between different points in the process, which

tell production when to make the next part. This saves warehouse space and

costs.

Philosophy

Philosophy of JIT is simple: inventory is waste. JIT inventory systems expose

hidden causes of inventory keeping, and are therefore not a simple solution for a

company to adopt.

JIT encourages businesses to eliminate inventory that does not compensate for

manufacturing process issues, and to constantly improve those processes to

require less inventory. Management may be tempted to keep stock to hide

production problems. These problems include backups at work centers, machine

reliability, process variability, lack of flexibility of employees and equipment, and

inadequate capacity.

In short, the just-in-time inventory system focus is having the right material, at

the right time, at the right place, and in the exact amount without the safety net

of inventory. The JIT system has broad implications for implementers.


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Advantages of JIT

Lower stock holding means a reduction in storage space which saves rent and

insurance costs

As stock is only obtained when it is needed, less working capital is tied up in

stock

There is less likelihood of stock perishing, becoming obsolete or out ofdate

Avoids the build-up of unsold finished product that can occur with sudden

changes in demand

Less time is spent on checking and re-working the product of others as the

emphasis is on getting the work right first time

Disadvantages of JIT

There is little room for mistakes as minimal stock is kept for re-working faulty

product

Production is very reliant on suppliers and if stock is not delivered on time, the

whole production schedule can be delayed

There is no spare finished product available to meet unexpected orders, because

all product is made to meet actual orders however, JIT is a very responsive

method of production


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Lean manufacturing:

A philosophy of production that emphasizes the minimization of the amount of

all the resources (including time) used in the various activities of the enterprise.

It involves:

identifying and eliminating non-value-adding activities,

employing teams of multi-skilled workers,

using highly flexible, automated machines

lean is centered on preserving value with less work. Lean is the set of "tools" that

assist in the identification and steady elimination of waste. As waste is eliminated

quality improves while production time and cost are reduced. Examples of such

"tools" are Value Stream Mapping, Five S, Kanban (pull systems), and poka-yoke

(error-proofing).

The implementation of smooth flow exposes quality problems that already

existed, and thus waste reduction naturally happens as a consequence. The

advantage claimed for this approach is that it naturally takes a system-wide

perspective, whereas a waste focus sometimes wrongly assumes this perspective.

Both Lean can be seen as a loosely connected set of potentially competing

principles whose goal is cost reduction by the elimination of waste. These

principles include: Pull processing, Perfect first-time quality, Waste minimization,

Continuous improvement, Flexibility, Building and maintaining a long term

relationship with suppliers, Load leveling and Production flow and Visual control.


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1.Eliminating Waste:

Overproduction : Make only what is needed now.

Waiting: Coordinate flows between operations, and balance load imbalances by

flexible workers and equipment.

Defective Products: Eliminate defects and inspection. Make perfect products.

2.Continuous Improvement breaks down into three basic principles:

1.Challenge : Having a long term vision of the challenges one needs to face to

realize one's ambition (what we need to learn rather than what we want to do

and then having the spirit to face that challenge). To do so, we have to challenge

ourselves every day to see if we are achieving our goals.

2.Kaizen : Good enough never is, no process can ever be thought perfect, so

operations must be improved continuously, striving for innovation and evolution.

3.Genchi Genbutsu : Going to the source to see the facts for oneself and make

the right decisions, create consensus, and make sure goals are attained at the

best possible speed.

3. Parallel Processing:

An important part of JIT manufacturing is to exploit parallel processing wherever

possible. Any operation being performed in series that can be performed in

parallel can take huge chunks out of manufacturing lead time. By doing product

design and process design simultaneously, the time to bring new products to

market is reduced.

4. Kanban Production Control:

Kanban cards are used to plan and control the movement of orders among work

centers. No parts can be produced or moved without a Kanban cards. Kanban is

based on the simple idea of replacement of container of parts, one at time.


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Techniques of lean manufacturing

5S, Kaizen, Six Sigma, Value Stream.

1. 5S

5 S is a tool for WASTE ELIMINATION. Probably one of the easiest lean

manufacturing processes to implement. It gets everyones attention, provides

immediate benefits and "makes sense" to almost anyone.

SEIRI (Segregation): Sort out unnecessary items in the workplace and discard

them

SEITON (Arrangement): Arrange necessary items in good order so that they can

be easily picked for use

-A place for everything

-Everything in its place

SEISO (Clean): Clean your workplace thoroughly so that there is no dust on

floors, machines and equipments

SEIKETSU (Standardize): Maintain high standards of workplace at all times

SHITSUKE (Discipline): Train people to follow good housekeeping discipline

automatically

2. Kaizen

This is Toyota's famous tool for continuous improvement. The idea is that

everyone in the organization re-examines their work and improves it in small

ways within their control.

Mini-Kaizens are like raindrops that add up to make a flood. This lean concept is

quite useful and easy for management to implement.


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3. Value Stream Mapping

Learn how to identify those areas that are producing waste and develop a map to

improve, using lean manufacturing methods. Once learned, this becomes an

internal process that changes the work environment permanently.

Many companies have used this concept to learn just where they currently are,

and how to get where they want to be. A great solution that can get people

involved.

4. Six Sigma

This is a method that enables you to measure your processes in order to improve

your bottom line. Once you get things organized, decide to continuously improve

your processes, and identify areas of waste, you need a way to monitor your

progress.

This engineering system keeps you on-track by monitoring your processes. You

use real-time examples from your own company to create track your programs.

Lean services

Lean principles have been successfully applied to call center services to improve

live agent call handling. By combining Agent-assisted Voice solutions and Lean's

waste reduction practices, a company reduced handle time, reduced between

agent variability, reduced accent barriers, and attained near perfect process

adherence.

Lean principles have also found application in software application development

and maintenance and other areas of information technology (IT). More generally,

the use of Lean in IT has become known as Lean IT.

The challenge in moving Lean to services is the lack of widely available reference

implementations to allow people to see how directly applying lean manufacturing

tools and practices can work and the impact it does have. This makes it more

difficult to build the level of belief seen as necessary for strong implementation.

However, some research does relate widely recognized examples of success in


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retail and even airlines to the underlying principles of lean. Despite this, it

remains the case that the direct manufacturing examples of 'techniques' or 'tools'

need to be better 'translated' into a service context to support the more

prominent approaches of implementation, which has not yet received the level of

work or publicity that would give starting points for implementers. The upshot of

this is that each implementation often 'feels its way' along as must the early

industrial engineers of Toyota. This places huge importance upon sponsorship to

encourage and protect these experimental developments.

WAITING LINE PROBLEM

Waiting lines are the most common phenomenon in our daily life. It affects

people, who need service at a number of places. These places, where one has to

wait in queue are: doctors clinic, bank counters, railway reservation counter,

telephone booth, fast food center etc. In manufacturing industry, queue or

waiting line is common in situations when machines have to wait for repair; semi-

finished item waiting in batches to be loaded on a machine; machine waiting for

operator or tool, etc. At airport, many times aero planes have to wait for

permission for take-off till a runway becomes free.

Some Applications of Waiting Line Problem

S.No

.

Application

Area Arrival Waiting Line Service Facility

1 Factory

Material/tool

s

In-process inventory

(WIP) Work stations

2Assemblyline

Sub-assembles WIP

Employees

currentlyprocessing the WIP

3

Machine

maintenanc

e

Repair tools

& equipment

Machines needing

repair Maintenance crew

4 Airport Plane Planes ready to fly Runway


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5 Bank Customer Deposit/withdrawal

Bank employee &

computer

6

Walk-in

interview Job seekers Applicants Interviewers

7Phoneexchange

Dialednumber Caller Switchboard

8 Govt. office Files Backlog files Clerks

9 Post office Letters Mailbox Postal employees

10

Executive

note

Dictation

note Letters to be typed Secretary

11

Grocery

shop Customers

Customer on the

counter

Checkout clerks

and bag packers

12

Traffic light

crossing Vehicles Vehicles in line Traffic signals

13

Car service

station Cars Unserviced cars Service facilities

14 Railways Passengers

Waiting passengers

on platform/waiting

room Trains

15 Tool crib Mechanics Waiting mechanics Store keeper

16 Hospital Patients Sick people

Doctor &

operation facility

Improving the Waiting Line System

In a waiting line system, managers must decide what level of service to

offer, A low level of service may be inexpensive, at least in the short run, but may

incur high costs of customer dissatisfaction, such as lost future business and

actual processing costs of complaints. A high level of service will cost more to

provide, and will result in lower dissatisfaction costs. Because of this tradeoff,management must consider what is the optimal level of service to provide. The

elements of the waiting line system are:

1. Customer Population the customer population can be considered to be finite

or infinite. When potential new customers for the waiting line system are affected


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by the number of customers already in the system, the customer population is

finite. When the number of customers waiting in line does not significantly affect

the rate at which the population generates new customers, the customer

population is considered infinite. In addition to waiting, a customer has other

possible actions. For example, a customer may balk, renege, or jockey. Balking

occurs when the customer decides not to enter the waiting line. Reneging occurs

when the customer enters the waiting line but leaves before being serviced.

Jockeying occurs when a customer changes from one line to another, hoping to

reduce the waiting time.

2. Service System the service system is characterized by the number of waiting

lines, the number of servers, the arrangement of the servers, the arrival and

service patterns, and the service priority rules.

Number of Waiting Lines waiting line systems can have single or multiple

lines. Banks often have a single line for customers. Customers wait in line until a

teller is free and then proceed to that tellers position. Other examples of single-

line systems include airline counters, rental car counters, restaurants, amusement

park attractions, and call centers. The advantage of using a single line when

multiple servers are available is the customers perception of fairness in terms of

equitable waits.

Number of Servers system serving capacity is a function of the number of

service facilities and server proficiency. In waiting line systems, the terms server

and channel are used interchangeably. It is assumed that a server of channel can

serve one customer at a time. Waiting line systems are either single server or

multi-server.

Arrangement of Servers services require a single activity or a series of

activities and are identified by the term phase. In a single phase system, theservice is completed all at once. In a multiphase system, the service is completed

in a series of steps, such as a fast-food restaurant with ordering, pay, and pick-up

windows.


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3. Arrival and Service Patterns waiting line models require an arrival rate and a

service rate. The arrival rate specifies the average number of customers per time

period. The service rate specifies the average number of customers that can be

serviced during a time period. The service rate is the capacity of the service

system. If the number of customers a business can serve per time period is less

than the average number of customers arriving, the waiting line grows infinitely.

Recommendations for Solving Long Lines

1. Determine acceptable time for the customers.

2. Try to divert the customers attention when waiting. This can be done by

providing music, a video, or some other form of entertainment that may help to

distract the customers from the fact that they are waiting.

3. Keep employees not serving the customers out of sight. Noting is more

frustrating to someone waiting in line that to see employees, who potentially

could be serving those in line, working on other activities.

4. Segment customers. If a group of customers needs something that can be done

very quickly, give them a special line so they do not have to wait for the slowercustomers.

5. Train servers to be friendly greeting the customer by name, or providing

some other special attention, can go a long way toward overcoming the negative

feeling of a long wait.

6. Encourage customers to come during the off-peak periods. Inform customers of

times when they usually would not have to wait; also tell them when the peak

periods are this may help to smooth the load.

jit,waiting line, 5 s,kaizen qualiyty mgmt techniques

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