Just In Time

What Is JITManagement philosophy (produce

only what is needed when it is needed)

A highly coordinated processing system in which goods move through the system, and services are performed, just as they are needed

Represents Pull type system

History of JIT ManufacturingEvolved in Japan after World War II, as a

result of their diminishing market share in the auto industry.

Toyota Motor Company- Birthplace of the JIT Philosophy Under Taiichi Ohno.

JIT is now on the rise in American Industries.

Definition JIT is a manufacturing philosophy

involving an integrated set of procedures/activities designed to achieve a high volume of production using minimal inventories

More IntroductionRaw materials, parts & sub

assemblies are pulled through the manufacturing process when they are needed.

Simply put, JIT is a philosophy of “make what is needed … when it is needed”.

Goal of JIT The ultimate goal of JIT is a

balanced system. Achieves a smooth, rapid flow of

materials through the system Eliminate disruptions Make system flexible Eliminate waste, especially excess

inventory

Summary of JIT Goals and Building Blocks

Product Design

ProcessDesign

PersonnelElements

Manufactur-ing Planning

Eliminate disruptions

Make the system flexibleEliminate waste

Abalancedrapid flow

UltimateGoal

SupportingGoals

BuildingBlocks

Big JIT – broad focus Vendor relations Human relations Technology management Materials and inventory management

Little JIT – narrow focus Scheduling materials Scheduling services of production

Big vs. Little JIT

What JIT Does Eliminates waste Achieves streamlined production Eliminate disruptions in production …

caused by poor quality, schedule changes, late deliveries.

Makes the manufacturing delivery system flexible by allowing it to handle a variety of products and changes in the level of output

Reduces setup and delivery times

Eight WastesTHE EIGHT TYPES OF WASTE OR MUDA

Waste Definition

1. Overproduction Manufacturing an item before it is needed.

2. Inappropriate Processing

Using expensive high precision equipment when simpler machines would suffice.

3. Waiting Wasteful time incurred when product is not being moved or processed.

4. Transportation Excessive movement and material handling of product between processes.

5. Motion Unnecessary effort related to the ergonomics of bending, stretching, reaching, lifting, and walking.

6. Inventory Excess inventory hides problems on the shop floor, consumes space, increases lead times, and inhibits communication.

7. Defects Quality defects result in rework and scrap, and add wasteful costs to the system in the form of lost capacity, rescheduling effort, increased inspection, and loss of customer good will.

8. Underutilization of Employees

Failure of the firm to learn from and capitalize on its employees’ knowledge and creativity impedes long term efforts to eliminate waste.

Sources of Waste

OverproductionWaiting timeUnnecessary transportationProcessing waste Inefficient work methodsProduct defects

Strategies For Minimizing Waste By Using JIT

Manufacturing in smaller lot sizes reduces excess inventory

Reducing inventory levels allows the problems to be uncovered … thus creating opportunities for manufacturing process improvement

Principles Of JIT Manufacturing

Total Quality Management

Production Management

Supplier Management

Inventory Management

Human Resource Management

1st Principle Of JIT

Total Quality Management

Total Quality Management

Seek long-term commitment to quality efforts with continuous improvement

Quality must be a higher priority than cost

Minimizing waste

Total Quality Management

Eliminate Quality Inspectors

Quality is everyone’s responsibility

Do it right the first time

2nd Principle Of JIT

Production Management

Production ManagementPull System vs. Push System

Pull = Made to order Push = Made for inventory

Flexibility of the system

Design For Testability – In the process Poka-Yoke= Mistake-proofing Throughout entire process

Production Management

Reduced lot sizes= Shorter cycle times

Eliminate disruptions in the process

Standardized Parts/ Simplicity

Production Management Communication Techniques

Completion of task-Kanban Problem- Siren/light

Stopping the process if something goes wrong =Jidoka

Preventive Maintenance

3rd Principle Of JIT

Supplier Management

Supplier ManagementEstablish Long Term Relationships

with few suppliers.

Delivery of Parts = 100% Defect Free Where they are needed When they are needed The exact quantity

Work Together

Supplier Management

Elimination inspection of parts

Communicate problems to suppliers in a positive manner.

4th Principle Of JIT

Inventory Management

Inventory ManagementEliminate Safety Stock = Zero

Inventory

JIT is not an inventory control system

Reduction in inventory opens up space

Inventory hides problems in a process.

Water Level = Inventory Rocks = Problems in the system Boat = Company Operations

5th Principle Of JIT

Human Resource Management

Human Resource ManagementCompany-wide Involvement

Motivation for continuous improvement Problem Solving High Employee Interaction

Build Pride In Workmanship

Human Resource Management

Self-Inspection of work

Diversified Employees Absenteeism To eliminate boredom in process

Management Support and Empowerment of workforce

JIT Manufacturing Building Blocks

Product designProcess designPersonnel/organizational

elementsManufacturing

planning and control

1. Product DesignStandard parts

Design Simplification

Highly capable production systems

Concurrentengineering

Design Simplification

2. Process Design

Small lot sizesSetup time reductionLimited work in processQuality improvementProduction flexibilityLittle inventory storage

Benefits of Small Lot Sizes

Reduces inventory

Less storage spaceLess rework

Problems are more apparent

Increases product flexibility

Easier to balance operations

Quality Improvement

Autonomation Automatic detection of defects during

production

Jidoka Japanese term for autonomation

Production FlexibilityReduce downtime by reducing

changeover timeUse preventive maintenance to

reduce breakdownsCross-train workers to help clear

bottlenecksUse many small units of capacityReserve capacity for important

customers

3. Personnel/Organizational ElementsWorkers as assetsCross-trained workersContinuous improvementLeadership

4. Manufacturing Planning and ControlPull systemsVisual systems (kanban)Close vendor relationshipsReduced transaction

processing (delays in delievery)

Preventive maintenance

Evaluation and selection of vendor (suppliers) network to develop a tiered supplier network – reducing the number of primary suppliers.

Transitioning to a Successful JIT System

Get top management commitment Decide which parts need most effort Obtain support of workers Start by trying to reduce setup times Gradually convert operations Convert suppliers to JIT Prepare for obstacles

Obstacles to Conversion

Management may not be committedWorkers/management may not be

cooperativeSuppliers may resist

Comparison of JIT and TraditionalFactor Traditional JIT

Inventory Much to offset forecast errors, late deliveries

Minimal necessary to operate

Deliveries Large Small

Lot sizes Large Small

Setup; runs Few, long runs Many, short runs

Vendors Long-term relationships are unusual

Partners

Workers Necessary to do the work

Assets

Comparison Of JIT & MRP

JIT Repetitive production Minimal shop floor control Simpler Relies on visual or audible signals to trigger production

and inventory (e.g. auto carpets) Lower inventories related to need “at the time” MRP Lot size or batch production Extensive shop floor control More complex Relies on computer system to trigger production and

order inventory Inventories related to batch or lot sizes

JIT in Services

The basic goal of the demand flow technology in the service organization is to provide optimum response to the customer with the highest quality service and lowest possible cost.

JIT Benefits Reduced Inventory Improved qualityLower costsReduced space requirementsShorter lead-time Increased productivityGreater flexibility Improved vendor relations

JIT Benefits (contd.)

Simplified scheduling & control Increased capacityBetter utilization of personnelMore product variety Increased equipment utilizationReduced paperworkValid production prioritiesWork force participation

JIT … Not For Everyone JIT concepts work best when goods can

be produced in response to consumer demand (e.g. automobiles, etc.)

JIT is less effective for the production of standardized consumer goods (e.g. basic clothing, food, soft drinks, toasters, etc.)

There are cases where JIT concepts apply to sub-processes of a make to stock environment. (e.g. computers etc.)

References Cammaranano, J. Lessons to be Learned: JIT. Atlanta, Georgia: Engineering

and Management Press, 1997. Dear, A. Working toward JIT: Management Technology. London: Derek

Doyle and Associates, 1988. Fisher, D. The JIT Self Test: Success Through Assesment and

Implementation. Chicago, IL: Irwin Inc., 1995. Hernandez, A. JIT Quality: A Practical Approach. Englewood Cliffs, NJ:

Prentice-Hall, 1993. Hutchins, D. Just-In-Time: Inventory Control. Brookfield, VT: Gower

Publishing, 1988. O’Grady, P.J. Putting the JIT Philosophy Into Practice. New York, NY: Nichols

Publishing, 1988. Reinfeld, N.V. Handbook of Production and Inventory Control. Englewood

Cliffs, NJ: Prentice-Hall, 1987. Schneiderjans, M.J. Advanced Topics In JIT Management: JIT Systems.

Westport, CT: Greenwood Publishing Group, 1999. Taver, R.W. Manufacturing Solutions for Consistent Quality and Reliability:

The 9 Step Problem Solving Process. New York, NY: AMACON, 1995. Wesner, J.W., Hiatt, J.M., and Trimble, D.C. Winning with Quality: Applying

Quality Principles in Product Development. Reading, MASS: Addison-Wesley Publishing Co., 1995.