Toyota Production System_final

8/6/2019 Toyota Production System_final

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Production StrategiesProduction Strategies -- Toyota Production SystemToyota Production System

Fachgebiet Montagetechnikund Fabrikbetrieb

Prof. Dr.-Ing. G. Seliger

Production Strategies

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Adam Smith

Adam Smith (1723 1790)

The division of labour

is limited by the extent of the market.

invisible hand of market exchange value utilization value free market for increasing wealth

Source: Smith, A., Wealth ofNations, 1776

Adam Smith


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Carl von Clausewitz (1780 1831)

Strategy is the use of combat for the

purpose of war.Carl von Clausewitz

Carl von Clausewitz

What is Strategy?

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Frederick Winslow Taylor(1856 1915)

Frederick Winslow Taylor

devised a system he called scientific management,a form of industrial engineering that establishedthe organization of work as in Ford's assemblyline.

pensum system initiative system

Frederick Winslow Taylor


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Henry Ford was the founder ofthe Ford Motor Company. He was

one of the first to apply assembly

line manufacturing to the massproduction of affordableautomobiles. This achievementnot only changed industrialproduction in the United Statesand the rest of the world, but alsohad such big influence overmodern culture that many social

theorists identify this phase ofeconomic and social history as

"Fordism."

Henry Ford (1863-1947)

Henry Ford

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Taiichi Ohno developed the mainobjectives just in time andautonomation after the second worldwar. He was the main developer of theToyota Production System.

Taiichi Ohno (1912 - 1990)

Taiichi Ohno


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The Total Avoidance of Waste

What is the Toyota Production System?

The main goal of theToyota Production System isto eliminate waste (= muda).

Eliminating of wastecompletely can improve theoperating efficiency by largemargin.

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Flexible Production


production in small lot sizes

mixed-Production for

production-levelling

alliance and synchronisation

of assembly and production

The ability to respond to

fluctuation in the market

has first priority, therefore:

Main Elements


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Justin

Time

Flexible Production


buffer free

store free

kanban (principle of a

Supermarket)

involvement of the supplier in

the kanban-system

Just in Time is delivery of the

needed amount at the righttime:

First Pillar

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Justin

Time

Flexible Production


Autono-mation

Autonomation (autonomous

automation) is the 100% zero defect

operation:

Apparatuses on every machine,

which can differentiate between a

normal and abnormal production

(Poka-Yoke).

In case any failure occurs (e.g.

defective work piece, wrong position

and navigation) the machine stops

automatically at the end of the work

cycle (Jidoka). This will be shown for

every worker on cards called Andon.

Second Pillar


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Toyota

Production System

Justin

Time

Flexible Production


Autono-mation

Using one of the main objectives

requires the simultaneous use of

all of the other main objectives.

Ohno says, that the individual

use of only one of the main

elements will not lead to a

successful implementation of

the Toyota Production System.

In contrast, a deterioration of

the production could occur.

Main Elements of the Toyota Production System

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What is waste?

Rate between work and waste



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Kinds of Waste(=muda):

Waste of overproduction

Waste of time on hand (waiting)

Waste in transportation

Waste of processing itself

Waste of stock on hand (inventory)

Waste of movement

Waste of making defective products

What is Waste?Source: Ohno, T., ToyotaProduction System, 1988

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Waste: The needless, repetitious movement that mustbe eliminated immediately. For example, waiting for orstacking subassemblies.

Non-value-added work: Waste, because there is noappreciation value, like getting components, opening asending of a supplier, pushing the on-button of engines.You have to change the working conditions if you wantto remove this waste.

Value-added work (under given working conditions):the real processing, which directly contribute to theappreciation value of the product.

Present Capacity = Work + Waste

Source: Ohno, T., ToyotaProduction System, 1988

Relation between Work and Waste


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Mass production of large lot sizes versus ToyotaProduction System with small lot sizes

Mixed production for production-levelling

How to achieve flexible production by selecting theadequate organizational type?

Flexible Production

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Source: Seliger, G.,Wirtschaftliche PlanungautomatisierterFertigungssysteme, 1983

Workpiece

Stationary in all processes Moving between process organisedcapacity units

Complete machiningon one single capacity

unit

Stationary machiningat the workpiece

(location principle)Capacity units combined

according to thecharacteristic of the partfamily (object principle)

Capacity units combinedaccording to the

characteristic of similartechnologies (performance

principle)

Pointproduction

Fixed-siteproduction

Job-shopproduction

Organisational Types of Production(1)


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Source: Seliger, G.,Wirtschaftliche PlanungautomatisierterFertigungssysteme, 1983

Capacity units combined according to thecharacteristic of the part family (object principle)

Different processsequences

Same processsequences

Synchronised flow ofmaterials

Flow of materialwithout

synchronisation

Transfer production

Automaticmaterial and

information flow

Flexible-productionsystem

Manufacturing cell

No bonding of thecapacity units

Capacity unitsinterlinked by feedsystem

Automatic flow ofmaterials, completesystem control

Flow production

Production withintegrated schedule flow

control

Production withintegrated anticipatedflow control

Production island

Serial production

Organisational Types of Production(2)

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batch delays arerunning towardszero, adjusted tochange, prefersutilisation ratio

balance

mixed flow ofproducts (many

variants)

only one product (fewvariants)

Flow of parts

low batch delays,order relatedproduction

smalllargeBatch size

shorter cycles,reduced

prefabricated-stocks, reduced

cycle time

processing andassembling are

directly connectedonly in assembling

Continuous flow ofmaterials

AdvantageToyotaFordAttribute

Source: Shingo, S., DasErfolgsgeheimnis der ToyotaProduktion, 1992

Difference between Ford- andToyota-System


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Ford produced 200 of type X at thebeginning of the month, 300 of type Y

in mid month and 400 of type Z at theend.

Avoidance of fluctuations at the final assembly line:

Toyota produced repeatedly a mix of X to Yto Z of 2 to 3 to 4. Constantly continuous flowof material in the assembly. No separation of

assembly and manufacture of components.

Mixed-model-Production in final assemblyNon-Mixed-model-Production in final assembly

Mixed production for production-levelling

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Process1

100 s 200 s 300 s

1 100

Process2

Process3

1 100

1 100100 s

100 s

Cycle time 300 s

Process1

100 s

Process2

Process3

1 2 3 98 99100

1 s

1 2 3 98 99100

1 2 100

1 s

1 s

3 s

Cycle time 102 s

Production in large batches Production in small batches

Short cycle times increase the flexibility to react to fluctuations.

Production in Large or Small Batches


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Process-orientated installation of a machine

Operation of more than one machine

Synchronisation by JIT with the Kanban-Tool

Just in Time

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The Toyota Production System is geared to the continuous flow process at thefinal assembly line. Through process orientated installation of the machines,every other production step will be adjusted to this continuous flow process.

Process orientated Installation of the Machines


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Turning machine

Milling machine

Planing machine

Drilling machine

A B C D

Versions handling

Turning machine

Milling machine

Planing machine

Drilling machine

A B C D

Versions handling

Multiple-machine operation Multiple-process handling

Parts towork on

Finish part

A worker is handling four variants of one

product in one handling process

A worker is handling four handling

processes involving four machines

Installation of Machines and Organisation

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Prevents overproduction and unnecessary transportNo tool will be produced or transported without kanban.

Provision of information regarding removal or transportSub purchaser cycle takes the amount of work pieces shown on thekanban.

Provision of production informationSub purchaser cycle produces the work pieces shown on the kanban inthe right amount and order.

The Tool Kanban (1)


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Used as a form of work order attached to goodsAlways attach a kanban to goods.

By knowing the cycle that caused the fault, defectiveproducts can be preventedDefective pieces will not be sent to the next cycle. The result are zerodefect products.

Discovers existing problems and allows checking ofstock.Reduction in amount of kanban leads to an advance of sensibility.

The Tool Kanban (2)

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Name of supplier Supplier gate

Assembly area

Number

Identification

Amount

A Kanban Card for a Supplier


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Removal of thekanban during theremoval of the firstcomponent fromthe new box.

The operatordeposits theKanban that he orshe removes fromboxes of parts in aKanban mailbox

nearby.

The team leadercollects all kanbansfrom the mailboxes atfixed points of time.This happens severaltimes a day. A postmanpicks up these

collected kanbans

and brings themto a sorting room.A machine sortsthe kanbans intodesignateddepositions for the

individualsuppliers.

Removal or Transport Information- Kanban(1)

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At a delivery ofcomponents adriver of thesupplier picks upthe kanbans fromhis box...

... and sorts theseagain in his factoryinto boxes.

A removal kanban willbe exchanged with aproduction-briefingkanban..

Removal or Transport Information- Kanban(2)


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100% error free production

SMED method (Single Minute Exchange of Die)

Andon

Poka-Yoke method

Kaizen method

Autonomation

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SMEDs arenecessary

assumptionsto minimisethe set-uptimes.

Lower set-uptimes reducethe cycletimes.

Source: Shingo, S., DasErfolgsgeheimnis der ToyotaProduktion, 1992 ( translated )

SMED (single minute exchange of die)

Keyholemethod

keyholes

Shaftslotsin here

Insert andremove here

Removed portion ofthread

Method withcountersunk

thread

U-shaped

Washers

Componentforattachment

diechangeunit

spring

Bracket

Lockingmechanism

method

U-slot method

springlock

Semi-circularslot

clamp

Clamp-method usingbolt tension


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Faster set-up times lead to an increase in machinecapacity.

Lower batch production leads to substantial stock reductions.

Fluctuation of demand is managed better because it is easier toreact quickly, e.g. if faster delivery times or a complete changeof a model are required.

The successful adoption of SMED gives the workers trust inconstant change. A special corporate culture leads to a

continuous process improvement (Kaizen).

Advantages of SMED

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In case of a defect the work piece doesnt fit into the tool.

The engine doesnt start if there is anything wrong with the tool.

In case of a defect the engine doesnt start.

In case of a defect or if a single step was left out the machine willautomatically correct it and continue the processing.

Irregularities will be located in the next cycle. The production ofdefect products can be stopped.

If a step was forgotten the next cycle doesnt start.

Poka-Yoke Method


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This mechanism is supposed toprevent a wrong orientation.

This mechanism interrupts theprocess if the nut is missing.

Examples for Poka-Yoke Method (1)

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Sensors provethe correct andexactpositioning.

Examples for Poka-Yoke Method (2)


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green light: business as usual

yellow light: worker needs assistance

red light: assembly line stops, a problem must be solved

It is ok to stop theassembly line becauseit helps to find allproblems.

Andon - Display Panel

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A standard process sheet has to

describe clearly and precisely these three elements:

Cycle timethe duration (minutes and seconds) in which one unit should beproduced.

Work progressionthe work order over time.

Standard inventorythe minimum of goods to get the flow process alive.

Standard Process Sheet


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Continuous improvement process

that is driven by the workers.

Colleagues construct the standard process sheets themselves.

Poka-Yoke and SMED are a result of kaizen.

Kaizen leads to an increase in motivation because workers can

influence their own conditions of employment.

Kaizen

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Ask yourself Why? Five times. That way you'll find the root cause,

and if you get rid of that it'll never happen again."Taichi Ohno

Why has the engine stopped? There was an overload and the fuse is burnt through. Why was there an overload? The bearing wasnt lubricated enough. Why wasnt it lubricated enough? The oil pump hasnt pumped enough. Why hasnt it pumped enough? The shaft knocked out. Why has the shaft knocked out? Because there was no sieve and therefore somesplinters got in the engine.

Ask yourself Five Times Why?


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Literature /

Ford, H.:

Today and Tomorrow: Corporate Leadership, Productivity Press, 1995

Taylor, F. W.:

The Principles of Scientific Management, 1st World Library, 2006

Womack, J. P. et al:

The Machine That Changed the World: The Story of Lean Production, Harper Perennial, 1991Clausewitz, C. von:

On War, Kessinger Publishing, 2002

Smith, A.:

Wealth of Nations, Prometheus Books, 1994

Monden, Y.:

Toyota Production System: An Integrated Approach to Just-In-Time, Engineering & Management Press, 1998

Ohno, T.:

Toyota Production System: Beyond Large-Scale Production, Productivity Press, 1995

Seliger, G.:

Wirtschaftliche Planung automatisierter Produktionssysteme, Hanser Verlag, Mnchen, 1983

Shingo, S.:

A Study of the Toyota Production System, Productivity Press, 1995Toyota Motor Cooperation:

The Toyota Production System, International Public Affairs Division, Toyota City, 1996

Documents

Toyota Production System_final