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International Journal of Production Research

ISSN: 0020-7543 (Print) 1366-588X (Online) Journal homepage: http://www.tandfonline.com/loi/tprs20

Toyota production system and Kanban systemMaterialization of just-in-time and respect-for-human system

Y. SUGIMORI , K. KUSUNOKI , F. CHO & S. UCHIKAWA

To cite this article:Y. SUGIMORI , K. KUSUNOKI , F. CHO & S. UCHIKAWA (1977) Toyota

production system and Kanban system Materialization of just-in-time and respect-for-human system, International Journal of Production Research, 15:6, 553-564, DOI:

10.1080/00207547708943149

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Published online: 28 Mar 2007.

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2/13

INT.

PROD

RES., 1977, VOL 15, No.6

553-564

Toyota

production s ys t em a n d

Kanban

system

Materialization

of

just-in-time

an d

respect-for-human system

Y. SUGIMORIt

KUSUNOKIt

F. OHOt

an d

8. UOHIKAWAt

Th e

Toyota

Production

System

an d

Kanban

S y st e m i n tr o du c ed

in

th is pa per

w a s d ev e lo pe d b y the Vice-President o f T o yo t a Mo tor C o mpan y . Mr.

Taiichi Oh no

and it was under

h is g ui d an c e that

t he se u ni qu e p ro du ct io n s ys te ms h av e

become

deeply rooted in

Toyota

Moter Company in th e past 20

years.

There

ar e

tw o

major

distinctive features in these

systems.

On e of these is t h e just-in-time production a

specially

important

factor

in

an

assembly indus try s uch as automotive manufacturing.

In.

this

type

of production


3/13

554

Y Sugimori et

al.

industries have their workers display their capabilities to

the

utmost. This

was

the

second thing

that Toyota

recognized.

Toyota production system and its basic concept

Upon

recognition of the

matters

related above,

Toyota

is planning

and

running it s production system on

the

following two basic concepts.

First

of all,

the

thing

that

corresponds to

the

first recognition

of putting

forth all efforts to

attain

low cost product ion is r educt ion of cost

through

elimination of

waste .

This involves making up a system

that

will thoroughly

eliminate waste by assuming

that anything

other

than

the minimum amount

of equipment, materials, parts,

and

workers (working time) which

are

absolutely essential to production

are

merely surplus that only raises the cost.

The thing that

corresponds to

the

second recognition of

Japanese

diligence,

high degree of ability, and favoured labour

environment

is to make full use

of the workers capabilities . In short, treat the workers as human beings

and

with consideration. Build up a system that will allow the workers to

display their full capabilities by themselves.

Cost cutting by tlwrough removal o waste

For materialization of this system, Toyota has attached special importance

t just-in-time

production and Jidoka

.

Distinguishing features o automotive industry In order to have

an

efficient production system in

the

automotive industry, it is required

that the

following

three

distinguishing problems be solved.

(1) The automot ive industry is a typical mass product ion assembly type

where each vehicle is assembled from several

thousand

parts

that

have

undergone numerous processes. Therefore , a trouble in

any of the

processes will have a large overall effect.

(2) There are very

many

different models

with

numerous variations

and

with large fluctuation in the demand of each variation.

(3) Every few years, the vehicles are completely remodelled and there

are also often changes at a

part

level.

The ord inary product ion control sys tem in such an industry consists

of fulfilling

the

production schedules

by

holding work-in-process inventory

over all processes as a means of absorbing troubles in th e processes and changes

in demand. However, such a system in practice often creates excessive

unbalance of stock between

the

processes, which often leads to dead stock.

On the other hand, it can easily fall in to the condition of having excessive

equipment and surplus of workers, which is

not

conformable to Toyotas

recognition.

ust

in

time production In

order to avoid such problems as inventory

unbalance and surplus equipment

and

workers, we recognized necessity of

schemes

adjustable

to conform with changes due to troubles and demand

fluctuations. For this purpose, we

pu t

our efforts in deve lopment of a pro

duction systemwhich is able to shorten the lead time from the

entry

of materials

to

the

completion of vehicle.


4/13

Toyota production system and Kanban system 555

The

just-in-time

production

is a

method

whereby

the

production lead

time is greatly shortened by maintaining the conformity to changes by having

all processes produce the necessary parts

at

the necessary time

and

have on

hand

only

the

minimum

stock necessary to hold

the

processes togeth,er .

In addition,

by

checking the degree of

inventory

quantity

and

production

lead time as policy variables, this produc tion method discloses existence

of surplus equipment and workers. This is the

starting point

to the second

characteristic of Toyota Production System, that is, to make full use of the

workers capability.

a Withdrawal by subsequent processes: The first requirement ofjust-in-time

product ion is to enable all processes to quickly gain accurat knowledge of

, timing and

quantity required .

In

the

general production system, this requirement is met as follows.

The production schedule of the product (automobiles in the case of auto

motive plant) is projected on

the

various parts schedules

and

instructions

issued to

the

various processes. These processes produce

the parts

accor

dance

with

their schedules, employing th e

method

of

the

preceding process

supplying the

parts

to its following process . However, it can be seen that

this kind of method

will

make it vastly difficult to attain production adaptable

to changes.

In order to material ize the first requirement, Toyota

adopted

a reverse

method of

th e

following process withdrawing the parts from

the

preceding

process instead of the

the

preceding process supplying the par ts to the

following process .

The reason for this is as follows: Just-in-time production is production of

parts by the various processes in the necessary amounts at necessary timing

for assembling a vehicle as a final product

of

the company.

such is the

case, it can be said that only

the

final assembly line that performs the vehicle

assembly is the process

that

can accurately know the necessary timing and

quantity of th e parts.

Therefore, the final assembly line goes to the preceding process to obtain

the

necessary

parts

at the necessary time for vehicle assembly. The preceding

process

then

produces on

the

parts withdrawn

by the

following process. For

the production

of these

parts,

the preceding process

obtains the

necessary

parts from

the

process

further

preceding it. By connecting up all of

the

process in chain fashion in this way, it will be possible for the entire company

to engage in just-in-time production without the necessity of issuing lengthy

production orders to each process.

b One piece production and conveyance: The second requirement of just

in-time

production

is

that

all processes

approach

the

condition where each

process can produce only one piece, can convey it one at a time, and in

addition, have only one piece stock

both

between the

equipment

and

the

processes.

This means that no process for any reason is allowed to produce extra

amount and have surplus stock between the processes. Therefore, each

process must approach the condition where it produces

and

conveys only


5/13

556 Y. Sugimori et al.

one piece corresponding to

the

single unit that is coming off

the

final assembly

line.

In

s ho rt, all the s ho ps are w ithh eld from lo t production and lot con

veyance.

Toyota has succeeded in reducing the lot size through greatly shortening

the

setup

time, improving production methods including

the

elimination

of in-process inventory within

the

process resulting from ordering

of

multi

purpose machining equipment in accordance with the processing requirements

for a product line,

and

improving conveyance resulting from repetitive mixed

loading. All of these

have

been carried out, including large numbers of

subcontractors.

c Levelling production:

Provided

that

all processes perform small

lo t

production and conveyance, if the quantity to be w ithd rawn by the subsequent

process varies considerably,

the

processes within the c om pa ny as well as the

subcontractors will maintain peak capacity or holding excessive inventory at

all times.

Therefore, in o rde r to

make

a just-in-time production possible,

the

pre

re qui si te will be to level

the production at

the. final ass embl y line t he m os t

important line that gives

ou t

the production ins tr uction s to all processes).

A de gree of this levelling is

determined by top

managers.

1) Final ass embly lines of Toyota are m ixe d

product

lines.

The

pro

duction per day is averaged

by

taking the number of vehicles in

the

monthly production schedule classified by specifications, and dividing

by the number of working days.

2) In r eg ar d to the production sequence during each day, the cycle time

of each different specification vehicle is calculated,

and

in order to

have all specification vehicles

appear at

their own cycle time, different

specification vehicles are ordered to follow each other.

the final as sembl y line levels the p ro du ctio n as related above, the

production

of

all processes practising subsequent process withdrawal

and

one

piece production and conveyance

are

also levelled.

The

second significant point in levelled p ro du ctio n is to ob serv e the basic

rule of just-in-time; to produce only as much as p os sibly s old, on the one

hand

adjusting i ts p ro du ctio n level accor ding to the chang e in market on

the other

hand pr od uc in g as s mo ot hl y as possible

within

a cert ain range.

ven

after the monthly production s chedule has b een decided, Toyota

w

still make changes among

the

different specification vehicles on

the

b as is of

daily orders, and even when it comes to the total number if there is necessity

to

meet

the changes in market conditions, Toyota will

make

revisions n the

monthly sc he dul e so as to re duc e the shock of market fluctuation as much as

possible.

When

the production system related above is compared

with

the generally

adopted

scheduled production system, the former

system can

operate

with

smaller production changes than the lat ter s ys tem. Con sequ en tly, it will be

possible to do with the less equipment capacity and more stable number of

workers. This is specially important to Japanese companies that have

lifetime employment system.)


6/13

Toyota production SY tem and Kanban system

557

A p rod uc ti on c ont rol s ys te m which ha s been de vel oped to p ra ct is e th e

above t hre e general rules is Kanban System.

d) Eli mi nat ion o waste from over-producing: Th e underlying concept in

jus t- in -time p ro du ctio n s ys tems is

that

t he va lue of e xi stence of i nv en to ry

is disavowed. .

In

th e

con ventio nal p ro du ctio n con tr ol s ys tem, existence

of

inventory

is app reciated as a means to abs orb trou bles and fluctuations in demand an d to

smooth fluctuations in load of processes.

In contrast

to this,

Toyota

sees the s to ck on hand as being only a collection

of troubles

and bad

causes. We consider

that

virtually most

of the

stock

on hand is th e result of over-producing more

than

th e a mo un t required,

an d

is

th e

worst waste

that

can raise th e production cost.

T he rea son

why

we consider i nv en to ry re sult ing from ove r-produc ing

is

th e

w or st w as te is

t ha t i t

hides

th e

causes of waste

that

should be remedied

such as unbalance between

th e

workers

and

between th e processes, troubles in

various processes, workers idle time, surplus workers, excessive equipment

capacity

an d

insufficient preventive maintenance.

Such latency of waste makes

it

difficult for workers to display their capability

an d it even becomes obstructive of an ever-lasting evolution of a company.

Jidoka: Th e t e rm Jidoka as used at Toyota m e a ns to make th e

equipment oroperation

stop

whenever

an

abnormal or defective conditionarises .

In short, its distinctive feature lies in

th e

fact

that

w hen an equipment trouble

or machining de fe ct h ap pe ns ,

th e

e qui pme nt or ent ire line stops,

an d

any

line with w or kers can be s to pp ed

by

them.

Th e reasons

for

Jidoka being so important are as follows:

1) To prevent m aki ng too much.

th e

equipment

is made to stop

when

th e

required

amount

is produced, making too

much

cannot arise.

Consequently,

th e

jus t- in -time p ro du ctio n can be accur ately carr ied

out.

2) Control of abnormality becomes easy. t will only be necessary to

make improvements

by

directing attention to th e stopped equipment

an d

th e worker who

di d th e

stopping. This is an important require

ment when making up

th e

s ys te m of full ut il iz at ion

of

workers

capabilities related next

Toyota

has mad e cou ntless n umber of imp ro vements to

realize

Jidoka .

u ll utilization o ioorkers capabilitie8

T hi s is T oy ot a s se cond ba si c conc ept

of

making

th e

best use of

Japan s

favoured labour

environment

an d excellent workers. t ha s built up a system

of

respect for human,

putting

emphasis on

th e

points as follows: 1) elimination

of waste movements

by

workers; 2) consideration for workers safety;

an d

3) self-display

of

workers capabilities

by

entrusting

them

with greater

responsibility an d authority

Elimination o Waste movement by workers: Workers ma y realize

their work

worthy

only if

th e

labour of diligent workers is exclusively used to

raise added value of products.


7/13

558

Y. Sugimori

et al.

Then

what ar e th e

waste movements

that

lower

added

value

an d

which

we must eliminate Th e first of these is workers movements accompanying

th e

waste

of making too much. Th e movements of material handling operations

between th e e qu ip me nt a nd between th e processes due to large inventory

are all waste movements.

t

has become possible for Toyota to effect large

reductions of this waste by makingup a system

that

allows thorough just-in-time

production.

However, even t ho ug h t he waste

of

making too much is reduced, it will

be of no avail if

th e

waste of worker s wait ing

time

is created as a result.

In th e

just in time production, even when there is surplus capacity in th e equip

ment, only as much as th e subsequent process has withdrawn is produced.

Thus, if

th e

equipment

an d workers are tied together, workers are subject to

idleness. To prevent such waste of waiting

time

being created, various

improvements

have

been

made

such as:

1 separating th e

workers from

th e

equipment by assigning a worker to multiple equipments; (2) concentration

of workers zones

at

th e

automatic

lines;

an d

(3)

making up

lines that do no t

require supervisory operation.

The second waste is to have th e workers perform operations that

ar e

by

nature not sui table for men. Operations inv.olving danger, operations in

jurious to health, operations requiring

hard

physical labour, an d monotonous

repetitive operations have been mechanized,

automated

an d unmanned.

T he t hi rd

waste

is workers movements as a

result

of troubles of defects.

Thorough Jidoka by

Toyota

has greatly reduced this

kind

of waste.

Considerations to workers safety: Workers of Toyota are diligent an d

enthusiastic about

attaining

production. Thus, he

may

not stop operation

if th e trouble is no t of a serious n at ur e a nd will take non standard methods

just to keep th e line. running.

waiting time occurs, he will become

impatient and

eventually start doing something extra. However, such kinds of

unusual operation or

extra

work are often accompanied

by

accidents, troubles,

or defects.

Th e

J i doka an d elimination of waiting time now being advanced by

Toyota is

no t

only for reducing the production cost,

bu t

also effective as a

measure for safety.

Th e results have been reflected in th e fact that from an international stand-

p oi nt t ho frequency rate of injury at

Toyota

is low.

Note: Comparison with th e frequency rate of injury in American

automotive

industry

shows

that

against th e 15 shown in th e

United

States

(ILO 1974 statistics), Toyota ha d 08 or about one-half lower.

Self display

workers ability: Nowadays, it ha s become an international

interest

to respect

humanity

of workers in production shops.

Toyota

firmly

believes that making up a system where th e capable Japanese workers can

actively

participate

in

running and

improving their workshops an d be able to

fully display their capabilities would be foundation of human respect environ

ment

of

th e

highest order.

As th e first

step

in this method, all workers at Toyota have a

right

to stop

th e

line on which they are working.


8/13

Toyota production system and anban system

559

Even in a long line like the final assembly line, if any abnormality comes

up such as

the

worker finding himself unabl e to keep up or discover ing an

incorrect or defective

part

he can

stop

the entire line

by

pressing

the stop

button near at hand. is not a conveyer that operates men, while it is men

that

o pe ra te a conveyer, which is

the

first

step

to r es pe ct for

human

inde

pendence.

As

the

second step, at all shops in Toy ota, the workers

are

informed of the

priority order of the parts to be processed and the s ta te of production advance

m ent . Therefore,

the

actual

authority

for decisions of job d is patching

and

o ve rt im e is d el ega te d to

the

foreman, and t hi s allows each shop to cond uct

production activities without orders from

the

control department.

As th e third step, Toyota has a s ys tem w hereby workers. can take part in

making improvements.

Any

employee at

Toyota

has a right to make an

improvement on

the

w as te he has f ou nd .

In the just-in-time production, all processes and all shops

are

kept in the

state

where they have no surplus so

that

if t roubl e is left, unattended

the

line will i mmedi at ely s top runni ng

and

will affect

the

entire

plant.

Th e

necessity for improvement can be easily understood

by

anyone.

Therefore, Toyota is e ndea vouri ng to

make

up a working place where

not

only

the

managers

and

foremen

bu t

also all w or kers

c I detect

trouble.

This is called visible control .

Through visible control, all workers

are

tak in g p os itiv e s teps to imp ro ve a

lot of

waste

they

have found.

And the authority and

responsibility for

running and improving

the

workshop have been delegated to the workers

thems elves, wh ich is

the

most dist inc ti ve fea ture of T oy ot a s re spe ct for

human system.

Kanban system

m

of anban ystem

A product ion control syste m for just-in-t ime product ion and making

full use of w or kers cap abilities is

the Kanban

S ys te m. Ut il iz ing

Kanban

System, workshops of

Toyota

have no longer relied upon an electronic computer.

is shown in Fi g. 1.

The

reasons to have employed

Kanban

System instead. of computerized

system are as follows:

1 ) Red uction of cos t proces sing inf or mation . calls for huge cost to

i mp le me nt a s ys te m that p rov id es p ro du ctio n s chedule to all

the

processes

and s up pliers as well as it s alterations

and

adjustments by real time control.

2)

Rapid and

precise aquisition

of

facts. Using

Kanban

itself, managers

of workshops may perceive s uch con tinu ou sly chang ing f acts as p ro du ctio n

capacity, operating rate,

and man

power

without

help

of

a computer. Hence,

data of schedules corresponding to

the

change are accurate, which urge work

shops to found responsibility systems

and

to promote activities for spontaneous

improvements.

3) L im it in g s ur pl us c ap ac it y

of

pre ce ding shops. Since

an

automotive

industry

consists of multistage processes, generally the demand for

the item

the part becomes progressively more erratic the further the process point

I.J.P.R. .

2

P


9/13

560

Y Sugimori et al.

Processing

and

:S8emblin

g

parts

J

Delivery instruction

of raw materials

Long term demand

forecast

New product planning

Current plant

capacity

l

Long term production planning

etermination of purchaae and ro i t plan

p r o d ~ t i o n foundation of

new

process Financial plan

Long-term production capacity pI nnlng

Annual

sales

planning

Annual production planning

Purchaae and

Production

Prof i t plan

countermeasure

against loads

Financial

plan

Middle term production

capacity planning

Monthly order

Monthly

production planning

Short-term production planning

various

preparation

for

production

Da11y

order

Production

scheduling

determination

of

delivery

date

Dispatching of Indivl sua l

order

~ ~ _ ....{ Assembling vehicles j

.



denotes instruction

of

purchase

parts

of large

subassemblies

carried by Kanban

Figure 1. Structure of production planning.

is removed from the

point

of the original

demand

for finished goods.

Pre-

ceding processes become required

have

surplus capacity,

and

it

is more

liable to

have waste

of over-producing.

3 Description Kanban system

I) In the

Kanban

System, a form of order card called

Kanban

is used. These

come in two kinds, one of which is called conveyance Kanban that is carried

when going from one process to the preceding process. The o ther is called


10/13

Toyota produc tWn. 8Y8temand I anban tem

561

, production Kanban and is used to order production of the portion with

drawn by

the

subsequent process.

These two kinds of Kanban are always attached to the containers holding

parts.

(2) When

content of

a container begins to be used, conveyance Kanban

is removed from

the

container. A worker

takes

this conveyance Kanban

and

goes to

the

stock

point of

the preceding process to pick up this

part

He then attaches this conveyance

Kanban

to th e container holding this part

(3) Then,

the

production

Kanban

'

attached

to

the

container is removed

and becomes a dispatching information for

the

process.

They

produce

the

part to replenish it withdrawn as early as possible.

(4) Thus,

th e

production activities

of the

final assembly line are connected

in a manner like a chain to

the

preceding processes or to the subcontractors

and

materialize

the

just-in-time production of

the

entire processes.

The flow of parts

and

Kanban are as shown in Fig. 2.

- ~ - 8 - - \ - T

_

-

-

-

-

-

\

I

I

: : I I

I

I

r I J I

,ustomer

I

I , :

I

I

:----.- -- --- -----1------

I

Part machining

Part assembling ; Final

assembling

I

.

Process

I

Process

.

Process

;

__ . ... .__. 1 . .__ --

Pi; Operation o f p ro ce ss i

I i ;

Part

inventory fo r process i

II Finished

good

inventory f or p ro ce ss i

; low Kanbsn

; Flo.., of par ts

Figure 2. Flow of parts and

Kanban,

The

equation for calculating

the number

of

Kanban

thl tt play

th e

most

important part in this system is as follows:

Let,

y

=Number

of

Kanban

=

Demand per unit

time.

T

w= Waiting time

of

Kanban

T

p

=Processing time.

a = Container capacity (not more

than

10of daily requirement).

ex =Policy

variable (not over 10 ).

Then,

y

D Tw+ Tp l ex .

=

a


11/13

562

Y. Su gimori

et

a

Notable points of operations of Kanban System meaning of the equation

computing number of Kanban

IIi order to materialize Toyota Production System

throughKanban

System,

we do

not

a cc ep t each f ac to r as a gi ven condition,

bu t

we

attach

importance

to mod if y each

by

means of positive improvements.

1) is a policy variable which is determined according to workshop s

capability to manage external interference.

2) D is det ermi ned with a smoothed demand.

3) Value of y is rather fixed de sp it e v ar ia ti on of D. Therefore, when

D increases, it is re qui red to reduce

the

v al ue of p Tw that is, a lead

time.

At

a workshop with insufficient capability of improvement,

they

cannot

avoi d overti me for a while.

They

m ig ht e ve n c ause line-st ops. H owe ve r,

the ult imate

o bjective of

Toyota

Production System is to visualize such

wastes as overtime andline-stop and to urge each workshop to become capable

in improvement. Incapable shops m igh t ha ve to cope

with th e situation

by

means of increasing

x

that

is,

number

of

Kanban

for

the

time

being. Hence,

the top

managers consider

the

v alue of

as

an

ind icator of s ho p cap ab ility in

improvement.

4) In the case that

demands

decreases, the lead

time

becomes relatively

larger. Consequently w as te of increasing idleness becomes visible, which

is an object of improvement called Syojinka --to decrease

the

number of

workers as demand production) decreases.

5) Work-in-process

inventory

could become

much

less

by

conducting

an imp ro vement to r ed uce

the

v alue of a x and p+

Tw .

What Toyota

considers as a goal t hr ou gh

Kanban

S ys te m r el at ed a bo ve

is

total

co nve yor line p ro du ct io n s ys te m c onne ct ing all

the

external

and

internal processes with i nvi sibl e conveyor lines. B ec ause , a

se t

of values of

x a and w is 0, 1, and 0, respectively, which means

nothing bu t

attributes

of a conveyor line. All

the

parts

that

constitute a vehicle

are

processed and.

assembled on a conveyor line, raising its a dded value. Fi nal ly they come ou t

as a completed vehicle one

by

one. On occurrence of troubl es,

the

whole

line may stop,

bu t

it b eg in s to mov e again immed iately . Toyota

Production

S ys te m is a scheme seeking r ea li za ti on of such an ide al c onve yor line s yst em ,

and

Kanban

isa conveyer connecting all the processes.

xpansionof just in timeproduction by reduction set up times of pressingdies

In

applying

the

concept

of

jus t- in -time p ro du ctio n for r ed uction of lead

times and work-in-process inventory, we faced difficulty in press shops practising

lot

p ro du ctio n. A fter discus sing a s olutio n of this difficulty in

lo t

production,

we concluded

that

lead time was proportional to set-up times, using the following

illustration.

Let,

T Operation time a day or 480 minutes.

S

Total

set-up time

for all products, assuming

that

S is

independent of sequence of products.

t

m f

Unit

processing time for the it h product.

d

f

Demand for th e it h product per day.


12/13

Toyota production system and anban system

x =ead time for all products in number

of

days .

i

Lot size for

th e ith product.

Then Tx=S L tm/d/x

i

Hence

563

x

Toyota A U.S.A.) B Sweden) C W.Germany)

Set-up time hour) 02 6

4

Number

ofset-ups a

day

3

1 05

Lo t

size 1 day-use

t

10 days-use

1 month-use

Strokes

per

hour 500-550

300

t

For

lessdemanded products below 1000units per month), as large as 7 days-use.

Table

1.

Press

plant

productivity characteristics hood

and

fender).

Takaoka

plant

of

Toyota A U.S.A.) B Sweden) C W.Germany)

Number of employees

4300 3800 4700 9200

Number of

outputs

a

day

2700

1000 1000

3400

Man-houra for

completion of vehicle

16 38 47

27

Table 2. Man-hours for completion of a vehicle in automotive assembly plants of

major counties.

Toyota A Japan)

B U.S.A.) C U.S.A.)

1960

41 13

7 8

1965 66 13

5

5

1970 63

13

6

6

Table 3.

Turnover

ratio of working assets

automotive companies of major

countries.

Year

Total number of proposals

Number of Acceptance

proposals per

capita

1965

9000

10

39

1970

40000

25 70

1973 247000

122 76

1976

380000

153 83

Table 4. Transit ion of number of annual proposals per capita

and

acceptance rate.


13/13

564

Toyota production system and nb n system

Lead time is

proportional

to set-up times for a given se t of

t

mf

and

l

for all

i 1.2 ... n And lot size for each product

f

is;

f df x f o r a l l i = I 2

Improvements

in

production

engineering

have

been

made

so as

to

reduce

set-up times since 1971. We

have

succeeded in reducing set-up time down

to 10

min at

800 ton-line pressing hood. fender

and

others. while

it

used

to take I hour. (Under

the present

condition of western countries, 4

to 6 hours as shown in Table 1.)

The result = the present condition of Toyota

As

related

above, Toyota has built up a unique production system through

its

history

of more

than

20 years. The results

are

as follows:

(I) Labour

productivity

is

the

highest among automotive industries of

major countr ies . (Table 2.)

(2) Turnover rate of working

asset

is also extremely high. (Table 3.)

3 Number

of proposals

and rate

of acceptance in a proposal

system

shows the condition

that

workers posi tive ly participate in

improvement (Table 4.)

La

aysteme

de

production

Toyota.

at

Ie

systeme Kenben presentee dans ca t article

ant

ete mis au point

pa r

Ie

Vice-President

de Is . Toyota. Motor

Company,

M.

Taiichi

Ohno at c eat BOUS sa direction

que

cee aya temea de

production

uniques ee sont

implantea

el

profondemenv

au eein de 8

Toyota. Motor Company

au COUTS des 20

dernieree enneee.

Ces

eyetemee comportent

deux.

carecterietiquea distinctives

principaJes: l une

d elles

es t 8

production

au momen t op portu n

,

un fecteur

epecialement,

important

dans une indus tr ie d easemblege

telle

que

Is.

fabrication

de

voitures.

Dans

ce

type

de

production,

seula les

produits

neceaaaires,

au momen t

neceasaire

at

en quant.ites necessairee ,

eont

fabriquee.

En

plus, les s tocks sont

mcintenue

au

minimum. La seconde e s t

Ie

respect

de

J etre humain

.

Dans

ce

systeme,

on permet eux

ouvriers

de reveler

toutea

leurs

capabifites

par une participation

active

8.

I exploitation

et

8.

I ameliorat-ion de

leurs propres ateliers.

Des Toyota

Produktionssystem un d de s Kanban System, welche

in

dieser Arbeit

vorgestel lt warden, wurden vom Viee-Prasidenten der

Toyota

Motor Company, Herm

Taiichi

Ohno,

entwickelt;

un d

unter seiner Leitung wurden diese einmaligen

Produktionssystem

in

den

letzten

20

Jahren

zu

einem fest verankerten Bestandteil der

Toyota. Motor

Company.

Diese Systeme

haben

vo r

allem

zwei

hervorstechende

MerkmaIe. Eines devon

is t

die C

gerade-zur-rechten-Zeit

-Produktion,

ein besondere

wichtiger

Faktor in

der Montegeindustrie,

wie

z.B. de r Kraftfahrieugindustrie. Bei

dieser

Ar t de r Produkt ion werden nur

die

notwendigen

Produkte, zur

notwendigen

Zeit, in

der notwendigen

Menge hergestellt, un d

die

Vorra.te

werden

au f

ein Minimum

BeschrAnkt. Zwe iteos handelt

es

sieh

bei

dem System urn ein I Respektierung des

Menschen

System,

in denen d en

Arbei te rn d ie

Moglich keit

gegeben wird ,

ihre

Fahigkeiten

voll

zu

entfalten, indem

sie

sich

aktiv

an d er O rganisa tion u nd d er

Verbesserung

ihrer

WerkBtii.tten

beteiligen.

REFERENCES

JAPAN INDUSTRIAL MANAGEMENT ASSOCIATION

1975,

Handbook of Industrial

Engineering

(in Japanese), (Tokyo: Maruzen).

M U R A M A ~ S U R., 1977, Production Planning and Production Control (in Japanese),

(Tokyo: Kigyo-Shindan-Tsushin-Gakuin); 1976, Production Control (in

Japanese), (Tokyo: Asakura-Shoten).

TOYOTA MOTOR

Co.,

LTD

1973,

Toyota Production System

(in Japanese),

(unpublished).

kanban in toyoyta

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