Just-In-Time

Presentation by-A.RAJ SHRAVANTHI

INTRODUCTIONAlso called Lean production or stockless production

JUST-IN-TIME/JIT is an approach which seeks to eliminate all sources of waste, anything which doesn’t add value in production activities, by providing the right part at the right place at the right time . just as they are needed!

Just-in-time manufacturing is a way of managing manufacturing systems that could reduce waste, and lower cost, thus increasing profit.

JIT- production is based on demand

History(1970) The realization for the new system came after

World War II when the Japanese automotive manufactures knew they were far behind the American motor companies.

JIT manufacturing is a result of limited demand, space, and resources in Japan compared to America.

Toyota Motor Company-( Birthplace of the JIT) Taiichi Ohno came up with a system that would

better fit Japan's capabilities.  JIT is now on the rise in American Industries.

Taiichi Ohno, Toyota officials in the 50s, known as FATHER OF JIT

JIT Goals and Building Blocks

Product Design

ProcessDesign

PersonnelElements

Manufactur-ing Planning

Eliminate disruptionsMake the system flexible

Reduce setupand lead times

Eliminate wasteMinimize inventories

Abalancedrapid flow

UltimateGoal

SupportingGoals

BuildingBlocks

JIT Building Blocks 1. Product design 2. Process design 3. Personnel/organizational

elements 4. Manufacturing

planning and control

1. Product Design Standard parts Modular design Quality

Poke-Yoke (Fail Safe) Design Change the process or resources Try to eliminate reliance on human

experience and knowledge Examples:

Color-coded parts Templates Use of counters on operations Design plugs to only be inserted one

way

2. Process Design Small lot sizes Setup time reduction Manufacturing cells Limited work in process Quality improvement Production flexibility Little inventory storage

Benefits of Small Lot Sizes

Reduces inventory

Less storage spaceLess rework

Problems are more apparent

Increases product flexibilityEasier to balance operations

Production Flexibility Reduce downtime by reducing

changeover time Use preventive maintenance to

reduce breakdowns Cross-train workers to help clear

bottlenecks Reserve capacity for important

customers

3. Personnel/Organizational Elements Workers as assets Cross-trained

workers Continuous

improvement Cost accounting Leadership/project

management

4. Manufacturing Planning and Control

Pull systems Visual systems Close vendor relationships Reduced transaction processing Preventive maintenance

JIT PurchasingLong-termLong-term

contracts withcontracts withsuppliers.suppliers.

Only a fewOnly a fewsuppliers.suppliers.

Parts deliveredParts deliveredin small lots.in small lots.

MinimalMinimalinspection ofinspection of

materials.materials.

GroupedGroupedpayments topayments to

vendor.vendor.

Pull/Push Systems

Pull system: System for moving work where a workstation pulls output from the preceding station as needed. (e.g. Kanban)

Push system: System for moving work where output is pushed to the next station as it is completed(eg:MRP)

Pre-JIT: Traditional Mass Production

Big lot sizesLots of inventory”PUSH” material to nextstage

Lowerper unit

cost

Big purchase shipments

Big “pushes” of finished goodsto warehouses or customers

???

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Post-JIT: “Lean Production”

Smaller lotsFaster setupsLess inventory, storage space”PULL” material to next stage

Minimalor no

inventoryholding

cost

Smaller shipments

Goods are pulled out ofplant by customer demand

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Tighter coordination along the supply chainGoods are pulled along

— only make and ship what is needed

Examples of Visual Controls 5S-CANDO (arranging) Jidoka or autonomation

Andon lights and buzzers announce tool status.

kanban squares, cards, containers. Lines on the floor to mark reorder points

Safety: colored labels for materials Statistical process control charts:

should be clearly visible.

5S-CANDO 5S-CANDO, a systematic approach to cleaning

and organizing the workplace, suppresses friction.

Seiri = Clearing up "When in doubt, throw it out."

Seitori = Organizing (Arranging) "A place for everything and everything in its place."

Seiso = Cleaning (Neatness) Shitsuke = Discipline Seiketsu = Standardization (Ongoing

improvement, holding the gains)

Kanban System( Kan=card, Ban= signal )

Kanban is the Japanese word meaning “signal” or “visible record”

Card or other device that communicates demand for work or materials from the preceding station

Paperless production control system Authority to pull, or produce comes

from a downstream process.

Kanban ExampleWorkcenter A Workcenter B

Workcenter B uses parts produced by Workcenter A

How can we control the flow of materials so that B alwayshas parts and A doesn’t overproduce?

Kanban card: Signal to produceWorkcenter A Workcenter B

Kanban Card

When a container is opened by Workcenter B, its kanban card is removed and sent back to Workcenter A.This is a signal to Workcenter A to produce another box of parts.

Empty Box: Signal to pullWorkcenter A Workcenter B

Empty box sent back. Signal to pull another full box intoWorkcenter B.Question: How many kanban cards here? Why?

Kanban No.Kanban No. 5678990 5678990 part No: part No: 66789X66789Xdescription description 16ga. 16ga.

Copper WireCopper Wireunits units Ft.Ft.reorder/lot qty reorder/lot qty 2020store location store location Row 12, Bin Row 12, Bin

66supplier supplier BICCBICCsupplier telsupplier tel 0208-891-0208-891-

01210121supplier part supplier part RT45502RT45502routing processName/location of next procesName/location of preceding

processcontainer type & capacitynumber of containers

released

What does a Kanban card look like?

Customer

Supplier

Supplier

Supplier

Supplier

Final Assembly

Fabric

Fabric

Fabric

Fabric Subass

Subass

Call (Kanban) & Pull

Call (Kanban) & PullCall (Kanban) & Pull

Summary JIT Goals and Building Blocks

Product Design

ProcessDesign

PersonnelElements

Manufactur-ing Planning

Eliminate disruptionsMake the system flexible

Reduce setupand lead times

Eliminate wasteMinimize inventories

Abalancedrapid flow

UltimateGoal

SupportingGoals

BuildingBlocks

(Work toward flexibility)Process flexibilityMachine flexibilityOperator flexibilityQuick changeover with short setup times

JIT goals Flexible enterprise; Only produce products

needed; Reducing the inventory in

process, finished goods and raw

materials; Reduce costs of

manufacturing; Creating space in the factory; Minor "lead time" in

manufacturing; Better customer service; Less waste; Greater return on investment.

The purpose of lean is to remove all forms of waste from the value stream.

Waste is ‘anything other than the minimum amount of equipment, materials, parts, space, and worker’s time, which are absolutely essential to add value to the product. — Shoichiro (Toyoda President,Toyota)

Understanding of friction, waste, or muda is the foundation of the lean Manufacturing. A job can consist of 75 percent waste (or even more).

The chief obstacle is the fact that waste often hides in plain sight

The role of inventory in traditional and JIT systems: The water and the rocks metaphor

Material quality problems Long

setups

Poor training Break

downs

Material handling

Traditional systems use inventory (water) to buffer the process from problems (rocks) that cause disruption.

Water = Inventory

The role of inventory in traditional and JIT systems: The water and the rocks metaphor

Material quality problems

Long setups

Poor training Break

downs

Material handling

JIT systems view inventory as waste and work to lower inventory levels to expose and correct the problems (rocks) that cause disruption.

The role of inventory in traditional and JIT systems: The water and the rocks metaphor

Material quality problems Long

setups

Poor training Break

downs

Material handling

Lowering the level of inventory is relatively easy to do. However, the problems that arise must be corrected quickly … Otherwise, without decoupling inventory, the process will flounder.

Material Waste Hides in Plain Sight

CleaningTank 1

CleaningTank 2

Dirty parts Clean parts

CleanWater

Discard water

CleanWater

The parts get clean, so no one questions this. What is wrong with this picture?

Why Not Make the Water Work Twice?

CleaningTank 1

CleaningTank 2

Dirty parts Clean parts

Discard water

CleanWater

The almost clean water from the second tank is good enough for use in the first tank. Water usage can be cut 50 percent.

Forms of Waste:

Overproduction Waiting time Transportation Processing Inventory Motion Product Defects

Recognize the Waste

This principle has been stressed by: Henry Ford Taiichi Ohno (Toyota production

system) Tom Peters (Thriving On Chaos) Shigeo Shingo J. F. Halpin (Zero Defects)

TPS Definitions of Waste1. Overproduction2. Waiting, including time in queue3. Transportation (between workstations, or

between supplier and customer)4. Non-value-adding activities5. Inventory6. Waste motion7. Cost of poor quality: scrap, rework, and

inspection

SEVEN WASTESJIT ALWAYS INSISTED ON ELIMINATION OF WASTES.SHIGCO SHINGO, A JAPANESE JIT AUTHORITY IDENTIFIES 7 WASTES. TO HIM BY ATTENDING TO THESE WASTE, THE IMPROVEMENT IS ACHIEVED. THOSE 7 KINDS OF WASTAGES ARE:

1.Waste of stocks.2.Waste of waiting.3.Waste of processing.4.Waste of defective production.5.Waste of over production.6.Waste of motion.7.Waste of transportation.

Summary JIT Goals and Building Blocks

Product Design

ProcessDesign

PersonnelElements

Manufactur-ing Planning

Eliminate disruptionsMake the system flexible

Reduce setupand lead times

Eliminate wasteMinimize inventories

Abalancedrapid flow

UltimateGoal

SupportingGoals

BuildingBlocks

Setup Reduction

Setup reduction is the process of reducing the time required to convert from production of the last good piece of unit A to the first good piece of unit B.

use methods engineering/common sense.

Ideal lot size = 1.

Setup Reduction (Cont.)

Setup activities: External: Operations performed while

the machine is running. Internal: Operations performed after the

machine is stopped.

Setup…responsibility of the operator.

Continuous Flow Production

Flow with JIT

Traditional Flow

CustomersSuppliers

Customers

Suppliers

Production Process (stream of water)

Inventory (stagnant ponds) Material

(water in stream)

SUMMARYKey Features of the JIT Approach

Smooth, uniform production rateSmooth, uniform production rate

Pull method of productionPull method of production

Purchase is small lot sizesPurchase is small lot sizes

Quick, inexpensive setupsQuick, inexpensive setups

High quality of materialsHigh quality of materials

Effective preventive maintenanceEffective preventive maintenance

TeamworkTeamwork

Multiskilled workersMultiskilled workers

Benefits of JIT:

The main benefits of just in time manufacturing system are the following:

1.Funds that were tied up in inventories can be used elsewhere.

2.Areas previously used, to store inventories can be used for other more productive uses.

3.Throughput time is reduced, resulting in greater potential output and quicker response to customers.

4.Defect rates are reduced, resulting in less waste and greater customer satisfaction.

Disadvantages of JIT:

• JIT REQUIRES SPECIAL TRAININGS WITH REORGANISATIONS OF POLICIES AND PROCEDURE.

• RESISTANCE TO CHANGE: JIT INVOLVES A CHANGE THROUGH OUT THE WHOLE ORGANISATIONS, BUT HUMAN NATURE RESISTS CHANGE.

• JIT REQUIRES MULTI-SKILLED WORKERS WITH FLEXIBILITY TO CHANGE. AND IT IS VERY HARD TO FIND THOSE WORKERS.

•Harley Davidson •Toyota Motor Company •General Motors •Ford Motor Company •Manufacturing Magic •Hawthorne Management Consulting •Strategy Manufacturing Inc.

Converting to a 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 Value chain mapping

References:

Operations & supply management- Chase, Ravi Shankar….

www.justintime.com Sdgi.com www.syspro.com