TPS Dr.gopal Iyengar

Kirloskar Institute of Advanced Management Studies, Yantrapur, Harihar – 577 602

Dr. Gopal Iyengar

TOYOTA PRODUCTION SYSTEM

A Seminar forIIMM, Mumbai

29 July 2006

Dr. Gopal IyengarDirector, KIAMS


Dr. Gopal Iyengar

Module 1 - Introduction

1.1) Evolution of TPS

1.2) Basic Ideas of TPS


Dr. Gopal Iyengar

Evolution of TPS In Taiichi Ohno’s Own Words

Birth of the System“…. The system was born through our various

efforts to catch up with the automotive industries of the western advanced nations after the end of the World War without the benefit of funds or splendid facilities”


Dr. Gopal Iyengar


Objective

“Above all, our most important purpose was to increase productivity and reduce costs”


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How did Toyota achieve its purpose?“To achieve this purpose we put our emphasis on the

notion of eliminating all kinds of unnecessary functions in the factory. Our approach has been to investigate the causes of various unnecessary steps in manufacturing operations one by one and to devise methods for their solution, often by trial and error”


Dr. Gopal Iyengar


Practical Nature of the System“Since the TPS has been created from actual

practices in the factories of Toyota, it has a strong feature of emphasising practical effects, actual practice and implementation over theoretical analysis”


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Network of Suppliers – Contributing Factor to Success

“In order to make TPS truly effective, we should recognise its limitations. Only if Toyota shares its destiny with surrounding cooperative manufacturers as a single community can it approach the perfect realisation of this system”


Dr. Gopal Iyengar

Basic Idea of TPS

Basic Idea

To maintain a continuous flow of products in factories in order to flexibly adapt to changes in demand. The realisation of such a production flow is called Just-in-Time (JIT) production at Toyota


Dr. Gopal Iyengar

Basic Idea of TPSJIT means• Producing only necessary items• In necessary quantities• At the necessary time

With This• Waste in all forms is eliminated• Turnover Ratio of Capital (total sales/ total assets

is increased


Dr. Gopal Iyengar

Basic Idea of TPS

Three sub-goals to support the main goal of Cost Reduction

• Quantity Control• Quality Assurance• Respect for Humanity


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Module 2 – Philosophy of TPS

2.1) Drastic Reduction of Costs

2.2) Elimination of Waste

2.3) Repeating ‘Why’ Five Times


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Philosophy of TPSDrastic Reduction of Costs

Achieved Through

• Small Lot Production• Frequent Delivery of Parts• Leveling of Production Volume• Reduction of Set-up Time


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Possible because of

• Multi-skill training of workers• Concentrated efforts to improve quality of

products


Dr. Gopal Iyengar


Achieved By Effective Application of

• Robots• NC Machine Tools• Machining Centres


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Philosophy of TPSElimination of Waste

Waste Defined1) An activity that does not add value to product or

service (Henry Ford)

2) Time, material and energy not turned into valuable product (Forcier and Forcier)

3) Anything other than the minimum amount of equipment, materials, parts, space and worker’s time essential to add value (Japanese perspective)


Dr. Gopal Iyengar


Three Types of Waste1) Muda – various non-value adding activities i.e.

wastes (7 + 2)i) Overproduction ii) Waiting

iii) Transportation iv) Processing

v) Inventory vi) Movement or Motion

vii) Defective Products viii) Expenses

ix) Paper Work


Dr. Gopal Iyengar


Three Types of Waste2) Muri – Activities which cause physical and/ or

mental strain; activities which are irrational or without any logic or reason

i) Layout ii) Tools/ Equipment Position

iii) Material Handling iv) Difficult, Dangerous, Dirty Actions causing fatigue

v) Non-standard Operations vi) Operator needing to

exercise visual control


Dr. Gopal Iyengar


Three Types of Waste3) Mura – Inconsistencies which hinder smooth

performance of work i) Material not as per specified hardness

ii) Having more than specified machining allowance

iii) Improper inflow of material causing waiting/ handling

iv) Improper machine functioning due to bad maintenance

v) Malfunctioning instruments

vi) Operator with inadequate knowledge


Dr. Gopal Iyengar


Motion Economy Principles1) Use of Human Body (9 principles)

2) Arrangement of Work Place (8 principles)

3) Design of Tools and Equipment (5 principles)

Refer handout for these 22 principles


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Different Interpretation of Waste Elimination1) Waste being produced due to inconsistencies or

variability

2) Variability is any deviation from optimum process that delivers a perfect product on time, every time

3) Causes: Non-conformance to specs, inaccurate drawings, producing without drawings, customer demand not known


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Approaches to Waste Elimination - Kaizen

Kai = Change Zen = Good

(Taken from 2 Chinese characters)

Kaizen change for the better, on a continual improvement basis. Kaizens are “incremental innovations”


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Approaches to Waste Elimination – 5S5S is a systematic approach to house keeping• Seiri Sort out unnecessary items• Seiton Arrange necessary items in good order “A place

for everything and everything in its place”• Seiso Clean the workplace, floor, machine free of dust• Seiketsu Maintain high standard of housekeeping and

work place organisation at all times• Shitsuke Train people to follow good housekeeping

autonomously


Dr. Gopal Iyengar

Philosophy of TPSRepeating Why 5 Times

5W1H Approach

Poem of the famous English poet, Rudyard Kipling

“I keep six honest serving men

Who taught me all I knew

Their names are What and Where and When

And Who and Why and How”


Dr. Gopal Iyengar


What ?

Where ?

When ?

Who ?

How ?

Why ?


Dr. Gopal Iyengar


Systematic Questioning

or Critical Examination• What – Purpose, What is being done

• Where – Place

• When – Sequence

• Who – Person

• How – Means

• WHY - THE MASTER QUESTION


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Why-Why Analysis

By asking ‘why’ 5 times and answering it each time, we can be sure to get to the root cause or real cause of a problem

Critical Examination Approach and Why-Why Analysis converge to lead to the correct solution


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Convergence Example (1/4)

Symptom – Repeated overheating of Spindle Head Housing

This relates to WHAT is the problem

• First WHY – Why is there repeated overheating?

First Answer – Because spindle head bearings and clutches get jammed

This shows WHERE the problem lies

(continued…2)


Dr. Gopal Iyengar


Convergence Example – continued (2/4)

• Second WHY – Why did the bearings and clutches get jammed

Second Answer – Because lubrication is not proper

This shows WHEN the problem occurs

(continued…3)


Dr. Gopal Iyengar


Convergence Example – continued (3/4)• Third WHY – Why is lubrication not proper

Third Answer – Because lubrication oil is not flowing freely

• Fourth WHY – Why is lubrication oil not flowing freely

Because lubrication lines are clogged

Third and Fourth answers show HOW the problem occurs

(continued…4)


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Convergence Example – continued (4/4)• Fifth WHY – Why are lubrication lines clogged

Fifth Answer – Because oil filters in the line are clogged. The line is not visible to the operator and so he does not clean it

Means to Solve the issue – Improve visibility of lines, so operator can take corrective action (clean them) and so prevent clogging


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Module 3 – Basic Framework of TPS

3.1) Pillar 1 – JIT

3.2) Pillar 2 – Autonomation (Jidoka)


Dr. Gopal Iyengar

Increase Profit

BASIC FRAMEWORK BASIC FRAMEWORK TPSTPS

Cost Reduction

Increase of net worth to total capital (B/S)

Increase of capital turnover ratio

Elimination of unnecessary items, specially Inventory

Continuous flow production

JIT Production

Autonomation

Production Method

Information system

Control by teamwork

Q C

Production smoothing

Design of Processes

Standardisation of

jobs

Kanban Yo-I-don & Andon

Baka-yoke

Small lot size

Short set-up time

Multifunction worker

Job finishing within cycle


Dr. Gopal Iyengar

Basic Framework of TPS Pillar 1 - JIT

In a flow process, the right parts needed in assembly reach the assembly line at the time they are needed and only in the amount needed. A company establishing this flow throughout can approach ‘zero inventory’


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JIT seeks to achieve the following:• Zero defects

• Zero Inventories

• Zero set-up time

• Zero breakdowns

• Zero handling

• Zero lead-time

• Lot size of one


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By Production Smoothing is meant that the preceding process has to produce only that quantity of units to replace those that have been withdrawn by the succeeding process.

• Production smoothing is a very important condition to achieve JIT

• It enables the system to adapt smoothly to variations in customer demand

• Minimisation of set-up times is very important to achieve production smoothing


Dr. Gopal Iyengar


Design of Processes

• Use of multi-process holding and multi-function worker (Shojinka)

• Creative thinking or inventive ideas (Soikufu)


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Standardisation of jobs is achieved through three means

i) Defining standard quantity of work in process

ii) Operations routing

iii) Determining cycle time needed


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Kanban Techniques control initiation of production and flow of material

• Get exactly the right quantity of items• At exactly the right place• At precisely the right time


Dr. Gopal Iyengar

Basic Framework of TPS Pillar 2 - Autonomation

Autonomation means to build-in a mechanism in machines or product lines to prevent mass-production of defective work

Autonomation is coined by Ohno from two words• Automation: of machines• Human: Processes controlled by human touch


Dr. Gopal Iyengar


Yo-I-Don: Empowering employees to take important decisions like (manually) stopping production when a problem is identified

Andon: The line stop indication board

Baka-Yoke: Innovations made to tools and equipment to automatically stop machines/ processes if quality deteriorates (Fool-Proofing)

Poka-Yoke: A device to permanently prevent recurrence of defects it is designed to eliminate(Fool-Proofing)


Dr. Gopal Iyengar


Yo-I-Don: Empowering employees to take important decisions like (manually) stopping production when a problem is identified

Andon: The line stop indication board

Baka-Yoke: Innovations made to tools and equipment to automatically stop machines/ processes if quality deteriorates (Fool-Proofing)

Poka-Yoke: A device to permanently prevent recurrence of defects it is designed to eliminate(Fool-Proofing)


Dr. Gopal Iyengar

Module 4 – TPS Pillar 1JIT Production Method

4.1) Process Design

4.2) Cellular Manufacturing

4.3) Single Piece Production Flow

4.4) Operations Scheduling

4.5) Multi-Function Worker

4.6) Set-up Time Reduction

4.7) Mixed Model Manufacturing


Dr. Gopal Iyengar

JIT Production - Process Design

• Process is the type of work done, methods used and activities defined and performed

• Material flow is a significant factor in process design

• Material flow is entirely dependent on how the process is designed and laid out in the plant


Dr. Gopal Iyengar


Flow of Production• Flow refers to the movement of materials through

the plant, • It assumes materials will not stagnate at any point

from raw material receipts to finished goods despatch

• Inefficient layouts, machine breakdowns, and other problems can interrupt smooth flow


Dr. Gopal Iyengar


• Flow should be linear i.e. scheduled by customer demand

• In flow, stoppage occurs only when value is being added or a critical activity performed

• In flow, when one machine is down all machines are down

• Objective of flow is a total business linear flow that requires minimum cycle time

• A relay race is an analogy of a linear process


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1) Cycle time is measured from the time a customer’s need is identified to the time payment is received for the finished product. Smooth flow reduces cycle time

2) Takt time is the desired time between units of production output synchronised to customer demand = Available time per day/ Required output per day – customer demand. Smooth flow essential to keep takt time


Dr. Gopal Iyengar


Cycle time can be reduced by

i) Adopting technology – expensive and often inefficient

ii) Simplify existing processes to eliminate waste or non-essential activities – inexpensive and relatively large savings


Dr. Gopal Iyengar


Coordinated efforts for Flow

i) Reduce changeover time

ii) Eliminate travel time between value adding steps

iii) Eliminate rework

iv) Integrate functions of design, process, maintenance to improve flow


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Impediments to Flow

1) In the Manufacturing Process – tool changeover, poor quality, shortages, bad layout, poor maintenance, poor process and engineering design

2) In Support Services – Changes in sales order, engineering changes, clerical delays, travel time, office time, downtime of office equipment


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Variability as impediment to flow

1) Variability is deviation from the optimum process that delivers a perfect product on time, every time

2) Variability occurs with unknown customer demand, non-standard units produced, specifications are inaccurate, produce parts without specifications


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Materials Handling and Flow• Materials handling connects individual parts of

the manufacturing system to form a whole• Less material handling, better the flow, as time

spent in waiting and transit is reduced• Any step to reduce set-ups and number of

processes will reduce material handling• Ideal – part should be made in one machine only


Dr. Gopal Iyengar


Plant Layout and travel time• Reducing travel time between machines/

processes/ departments aids smooth linear flow• Benefits are : reduced WIP; reduced costs of

material handling equipment, workforce and floor space


Dr. Gopal Iyengar


Line Balancing and flow• In flow, all functions and machines are

interdependent• A process can produce only as much as the

lowest-output machine (bottleneck)• Balancing the line means producing same

quantity per unit of time at each operation


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Bottlenecks• Relates to capacity – one or more processes have

lesser capacity than required process output• Bottlenecks imply capacity shortage is a

permanent phenomenon• Breakdowns/ materials shortage cause temporary

bottlenecks


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Bottlenecks restrict throughput• Limiting factor of a process output• Level of utilisation of a non-bottlenec is

determined by bottleneck• Balancing flow means no bottlenecks• Improving non-bottleneck operations is of less

value than improving bottleneck operations


Dr. Gopal Iyengar


Relieving bottlenecks• Keep machine operating longer• Preventive maintenance to have fewer

breakdowns• Add another machine


Dr. Gopal Iyengar


Veena to type table 6B, page 80/ 86Operation Required Time Output per unit Approx. Output

No Hours Per Hour, Units[A] [B] [C=60/B] [D]

1 4.8 12.5 12

2 10.2 5.9 6

3 5.1 11.8 12

4 9.9 6.1 6


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• In the previous table line is NOT balanced • Twice as many units can be produced in the first

and third operations compared to second and fourth operations (bottlenecks)

• WIP accumulates at second station or third station operates at 50%

• Let operations 2 and 4 (bottlenecks) have two machines/ operator


Dr. Gopal Iyengar


• Line Balancing is a design of process problem to eliminate bottlenecks. It depends on capacity needed for future demand at a specified time

• Bottlenecks are due to low output, slow speeds, frequent breakdowns.

Two approaches to balance a line

1) Occasional shut down of high output machine

2) Increase capacity of bottleneck machine


Dr. Gopal Iyengar

JIT Production Cellular Manufacturing

Layouts

1. Process layout – low volume, high variety – job shop

2. Process layout – high volume, low variety – transfer lines

3. Cellular layout – combines high volume and variety – makes a family of parts flexibly


Dr. Gopal Iyengar


Receipt

Of

Order

FINAL

ASSLY.

Saw GrindPress Weld Paint

Lathe Lathe Lathe Sub-Assly

Sub-Assly

Warehouse

Ware-house Ware-

house

Heat Treat

Process-Oriented LayoutProcess-Oriented Layout


Dr. Gopal Iyengar


Saw Grind

Receipt

HeatTreat-ment Pain

tLathe

Lathe Sub-Assly

FinalAssembly

Product-Oriented LayoutProduct-Oriented Layout

Weld

Fabrication Subassembly


Dr. Gopal Iyengar

Parts

““Cell” Manufacture For JITCell” Manufacture For JIT

Parts

Parts

O

O

O

O

O

O

O

O

O O


Dr. Gopal Iyengar


Features of Cells1. Flexibility of routing – less than process, more than

product layout

2. Material flow – better than process, lesser than product

3. WIP – lesser than process, similar to product

4. Lead times – shorter than process, similar to product

5. Volumes – medium, process low, product high


Dr. Gopal Iyengar


Cellular Design eliminates waste of

1. Motion

2. Waiting Time

3. Inventory

4. Floor Space


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JIT Production Single Piece Production Flow

Steps to achieve single piece production flow

1) Multi-skilled workers

2) U-shaped layout for handling multi-processes

3) Reduce set-up time

4) Standard combinations of operations

5) Greater teamwork and coordination


Dr. Gopal Iyengar

JIT Production Single Piece Production Flow

“Make today what is sold yesterday”

“Make now what is sold now – in single pieces”

Results in:• Fewer workers• Less equipment• Less Warehouse space• Fewer managers


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JIT Production Operation Scheduling

Levels of Planning (top-down)• Vision and Mission, Goals and Objectives• Corporate and Business Strategy• Operations Strategy• Capacity Planning• Master Production Schedule – weekly• MRP – operational planning, daily


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Veena to draw 9.1, 114/120


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• MRP and MRP II• MRP is push system• Has problems when sales forecast is wrong, no

capacity planning, no feedback of production v/s plan

• MRP II includes Capacity Planning, Other resource planning like Finance, Production Schedule – but is still a (refined) push system


Dr. Gopal Iyengar


JIT – Pull System, with stabilised MPS• Use Kanban, not forecast for production control

• Plan MPS for a fixed period – say a month - to plan work schedules

• Within the month, the MPS is leveled (same quantity) on a daily basis – Kanban quantities. This is Production smoothing

• Transfer plan to all work centers and suppliers


Dr. Gopal Iyengar

JIT Production Multi-Function Worker

Design processes for• Multi-process holding, Multi-function worker (Shojinka)

and Creative thinking (Soikufu)

• Multi-function worker provides flexibility, promotes teamwork and increases productivity

• Creative thinking uses workforce knowledge and experience to uncover and solve problems)

• Multi-functioning includes machine cleaning, simple maintenance and 5 S participation


Dr. Gopal Iyengar

JIT Production Set-up Time Reduction

• Total time = set-up time (non-productive) + operations time (productive)

• Set-up time decided by number of set-ups and time per set-up

• Reducing set-up time increases available capacity and flexibility, and reduces inventory

• As set-up time approaches zero, lot size of one is approached


Dr. Gopal Iyengar


Driving down set-up time

1. Use two set of dies

2. Have quick-change adjustments

3. Employ ‘cleverly’ designed tools and fixtures

NOTE: Economic Batch Quantity balances set-up cost and inventory carrying cost. Driving down set-up time reduces set-up cost & EBQ tends to one


Dr. Gopal Iyengar


SMED – key technical breakthrough to move to Pull system and One-piece flow

Divide die-changing to two components

1. IED (Inside Exchange of Dies). Performed only after machine is stopped e.g. mounting the die

2. OED (Outside exchange of Dies). Performed when machine is running e.g. transporting dies to machine


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Phases in SMED

1. Identify IED and OED

2. Target delays in IED for elimination

3. Convert as much IED as possible to OED

4. Reduce IED time by: eliminating adjustments, simplifying attachments and detachments, streamlining clamping methods, one touch exchange of dies


Dr. Gopal Iyengar

JIT Production Mixed Model Manufacturing

Mixed Model manufacturing

ABC ABC ABC and not AAA BBB CCC• This helps to balance output in terms of daily/ weekly

requirements of the individual product rather than produce in batches, aligned to customer demand

• Inventory gets significantly lower

• Mixed mode can be adjusted to pull

• Low set-up and cellular manufacture help mixed-mode


Dr. Gopal Iyengar

Module 5 – TPS Pillar 1JIT Information

5.1) Kanban System

5.2) Comparing Kanban and MRP


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JIT Information Kanban System

Kanban

1) In Japanese, Kanban means ‘marker’. It is a card that signals need for another container of material

2) Each Kanban corresponds to a standard quantity of production quantity

3) Kanban carries vertically and laterally within a company and to suppliers also


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• Kanban was derived two-bin inventory system• Here the first bin is eliminated. The second bin

has Kanban quantity. When that is taken for consumption, the kanban triggers the same quantity to be made

• Use of Kanban cards pulls production through the system rather than push it through the system. This prevents overproduction and inventory


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Types of Kanbans• Withdrawal – authorises moving one kanban

quantity from preceding to subsequent station• Production Kanban – authorises production of

kanban quantity in preceding station• Subcontract Kanban: Instructs subcontracted

supplier to deliver kanban quantity


Dr. Gopal Iyengar


Types of Kanbans (continued)• Emergency Kanban – Temporarily issued

fordefective work, extra insertions or spurt in demand

• Special Kanban – for job orders

• Signal kanban – Used whn lot production takes place in job-oriented production. It is triangular, and placed at a ‘ROL’ level to the bin. Operates similar to ROL


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Types of Kanbans (continued)• Combination Kanban – A cart is used to physically

move to preceding station like a withdrawal Kanban

• Electric Kanban – For fully automated processes (like a transfer line). No workers. Material moves from station A to B automatically, triggered by Electric Kanban. Only at first station loading is done

• Other variations: colour code raw materials Kanban.


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Kanban Rules

1) Subsequent process withdraws from preceding process the necessary quantity at necessary time

1.1) Withdrawal without Kanban is prohibited

1.2) Withdrawals greater than number of Kanbans is prohibited

1.3) Kanban should always be attached to the physical product


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Kanban Rules (continued)2) Preceding process produces quantities withdrawn by

subsequent process, initiated when the withdrawal takes place

2.1) Production greater than number of Kanbans is prohibited

2.2) Sequence of production of variety of parts in same process should follow the sequence in which each Kanban was delivered


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Kanban Rules (continued)2.3) Where set-up change is needed in preceding process, it

should be quick

2.4) If Kanban quantity is equal to re-Order Point, production must start immediately


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Kanban Rules (continued)

3) Defective products should never be sent to subsequent process.

4) Number of Kanbans should be minimised

5) Kanban system should be used to adapt to only small fluctuations in demand


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Adapting to Demand Fluctuation

• Minor fluctuations are met through temporary increase of capacity like overtime (10-30% variation in demand can be met by changing frequency of Kanban transfers, without revising the number of Kanbans

• Kanban cannot cater to major seasonal changes. These should be dealt as production smoothing


Dr. Gopal Iyengar


Two other Kanban concepts1) Whirligig Beetle (Mizusumashi) – A forklift moves

moves through various processes picking up parts for subsequent processes

2) Round Tour System: If 4 suppliers need to supply parts 4 times a day to the line, the first supply is by supplier A who picks up required parts from B, C, D also. Second supply is by B who picks up parts from A, C, D also. And so on.


Dr. Gopal Iyengar


Determining number of Kanban cards (containers)1) Let n = total containers/ kanban cards, D = demand rate

of succeeding (using) centre (2 parts per minute), C = container size in number of parts (25), T = lead time for a container to complete a full circuit of fill, wait, move, used and return to fill (100 minutes)

2) Number of containers n = DT/C = 2*100/25 = 8

3) Maximum inventory = nC = DT = 8*25 = 200

4) Reducing lead time (T) is the key to inventory control


Dr. Gopal Iyengar


Advantages of Kanban

1) Containers are small and standardised – control inventory

2) Emphasis is on meeting schedules, reducing time and cost of set-up, economical material handling

3) Kanban is a visible system – easily worked

NOTE: Kanban is suitable only for repetitive production and the demand is reasonable stable


Dr. Gopal Iyengar

JIT Information Comparing Kanban and MRP

1) Kanban is pull, MRP is push

2) MRP is based on sales forecast, Kanban on a repetitive master Schedule of shorter duration

3) MRP results in build for stock, Kanban results in build for demand

4) In MRP production peaks and falls in a month, in Kanban production is smooth

5) Kanban highlights and reduces wastes like long set-up time, lower inventory, lower total cycle time


Dr. Gopal Iyengar

Module 6 – TPS Pillar 2Autonomation (Jidoka)

6.1) Andon

6.2) Yo-I-Don

6.3) Poka-Yoke


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Autonomation - Andon• Autonomation (or Jidoka) is developed to give

machines the intelligence to stop automatically as soon as an abnormality occurs and send a signal to draw the operator’s attention

• This is achieved by using light signals called Andon - meaning ‘lantern’ in Japanese

• Andon light is used to expose abnormalities immediately so that they can be controlled


Dr. Gopal Iyengar

Autonomation - Andon• World class operations quickly identify problems

(abnormalities) and respond to it.

• Autonomation (or Jidoka) is developed to give machines the intelligence to stop automatically as soon as an abnormality occurs and send a signal to draw the operator’s attention

• This is achieved by using light signals called Andon - meaning ‘lantern’ in Japanese

• Andon light is used to expose abnormalities immediately so that they can be controlled


Dr. Gopal Iyengar

Autonomation - AndonProblem Identification in Automatic Operations

This can be achieved by giving intelligence to the machine to sense the abnormal. Examples:

1. A limit switch to sense need for replenishing raw materials

2. Fixing a counter to stop a machine for maintenance after a pre-determined number of cycles are over

3. Fixing a timer for a fixed time operation


Dr. Gopal Iyengar

Autonomation - AndonProblem Identification in Automatic Operations (contd)

• When the ‘intelligence’ makes the machine stop, a buzzer and a light go on

• The buzzer draws the operator’s attention that an abnormality has occurred

• The lamp pinpoints the location – Andon

• Green light shows machine is working okay (normal). Yellow shows ‘requires attention’(defects happening) before it leads to stoppage. Red light shows stoppage (parts shortage)


Dr. Gopal Iyengar

Autonomation - AndonTypes of Andon

1. Paging Andon (Yellow) – to request material replenishment

2. Emergency Andon (Yellow) – to indicate abnormalities

3. Operation Andon (Green) – all is okay

4. Progress Andon – Different Andons on different interconnected lines


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Autonomation – Yo-I-DonYo-I-Don

• It is indicative of “Ready, Set and Go”

• It is an autonomation method using andon and specially applied in group processes

• Group processes are generally made of sub-processes (cells) which all work synchronously as per takt time.

• If any process is lagging behind, process operators use Andon lights to control speed of the process. Process operators have authority to stop the line


Dr. Gopal Iyengar

Autonomation – Yo-I-DonYo-I-Don• Yo-I-Don Lights is like call buttons for airline hostesses

• If a sub-process is unable to finish in the takt time, or an operator needs major help, he can switch on the red light

• If operator needs temporary/ minor help, he can switch on the yellow light

• If all is well and within takt time, it is green light. If all Yo-I-Dons of a linked process are green, it is working synchronously

NOTE: Yo-I-Don lights are for a cell. They are in addition to Andon lights of individual proceses of the cell


Dr. Gopal Iyengar

Autonomation – Yo-I-DonComparing Andon and Yo-I-Don

• Both use lamps to communicate status of operation, draw attention of operator/ supervisor, attend the problem and set it right

• Andon draws attention to one operation within a multi-machine/ multi-operation set up

• Machine stops automatically when process is over or problem occurs

• Used in unlinked cells/ process units


Dr. Gopal Iyengar

Autonomation – Yo-I-DonComparing Andon and Yo-I-Don

• Yo-I-Don is applying andon to group working and multi-cell working

• This ensures takt time is maintained by all the linked processes

• The lagging or delaying process can be helped so that overall takt time is maintained


Dr. Gopal Iyengar

Autonomation – Poka-YokePoka-Yoke

• Japanese word meaning fool-proof mechanism

• Fool-proofing or mistake-proofing prevents operatos from committing a mistake in the process

• Poka-Yoke identifies areas requiring operator’s visual attention & eliminates need for visual attention

• It makes operation fool proof by stopping machine if anything wrong is attempted

• Helps reduce inspection time in succeeding process


Dr. Gopal Iyengar

Module 7 – TPS Support Function

7.1) 5S

7.2) JIT Purchasing


Dr. Gopal Iyengar

TPS Support Function – 5S5S gives five good housekeeping concepts

• Seiri – Sort out unnecessary items

• Seiton – Arrange items in good order – a place for everything and everything in its place

• Seiso – Clean workplace thoroughly

• Seiketsu – Maintain high standards of housekeeping always

• Shitsuke – Train people to follow good housekeeping autonomously


Dr. Gopal Iyengar

TPS Support Function – 5SFunctional Influence of 5S

• Safety – as place is well organised

• Efficiency – improves at an organised workplace

• Quality – not hampered as the place is clean

• Elimination of breakdown – correct labeling prevents a wrong button being pushed, leading to problems

• Helps in Quality, Cost, Time efficiencies

• Searching for Something – Sagasu – leads to waste


Dr. Gopal Iyengar

TPS Support Function JIT Purchasing

JIT Purchasing

• Right parts in right quality at right place and time through supplier cooperative relationship

• JIT Purchasing eliminates waste and non-value added items, effective implementation of kanban, continuous process improvement

• Reduced supplier base helps to achieve the above


Dr. Gopal Iyengar

TPS Support Function JIT Purchasing

Advantages of reduced number of suppliers

1) Manage quality than quantity

2) Less paper work

3) Work closely with suppliers

4) Economies of scale

5) Reduce variability of supplies

6) Easier coordination

7) Easier quality certification of supplier


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar


Dr. Gopal Iyengar

Documents

TPS Dr.gopal Iyengar