Pokayoke Treatment

JICA ExpertMaster EngineerKenji TAKEMURA

Mankind is an animal which makes mistake

POKAPOKA--YOKEYOKE

8:30--

by Selected few

by Everyone

*Background ? *Organization ? *Management ?*Example ? *Start ?

QCC TQM TPM

P Q C D

JIT

Morale &Discipline

5S

Collecting data

Analyzing data

Finding problem

Countermeasure

Implementation

Checking result

QC Tools

I.E.

Statistics

Technological Process

KAIZEN

SuggestionScheme

The frame of Practical Technologies for Productivity

by K. Takemura

KANBANPOKA-YOKE

PRACTEC.PPT

Method of

KAIZEN

-9:00

POKA-YOKE

Mankind is an animal which makes mistake

Admitting( affirm ) mistake and hating( deny ) those whomade mistake.

Hating( deny ) mistake and admitting( affirm ) those whomade mistake.

Which idea do you take ?

1. What does POKA-YOKE means?

*POKA: Careless mistake*YOKE: to avoid

Fail Safe or Fool Proof

In Japanese.

人を責めることが楽だから

～9:15

Tools

Habitual etc.,Discontinuation etc.,DiscontinuationMany

InterruptionThinPoor memoryBrokenLow attentionSimilar

BusyNoisyNo concentrationSmall

TiredDarkForgetMistake

P O K A

Exercise: Why we make POKA?

～9:25

How does a mistake ( POKA ) take place ?

There are some kinds of mistake. The causes of these POKA mostly lead to people.

1. POKA by Carelessness

2. POKA by misunderstanding

3. POKA by brief look

4. POKA by novice ( amateur )

5. POKA by selfishness

6. POKA by dull-witted

7. POKA by irresponsibility

8. POKA by mal function

9. POKA on purpose

Thoughtless mistake. Driving a carin a crossing with red signal.

Braking an automobile instead ofclutch while driving automatic car.

Mistake red signal as yellow oneby brief look while driving.

A novice driver only concentrate ondriving. and forget to stop.

Crossing a road while red signalbecause everyone does so.

Late for braking a car because oneis slow in judgment and action.

A novice is irresponsible because of no correct training for him

Brake suddenly does not workwhile driving

Violation. Crossing a road while redsignal on purpose.

Type of POKA Examples while driving Countermeasures

Periodical confirmation and inadvance. Confirmation by call.

Confirmation in advance. Meeting.Operation standard

Meeting. Caution.Confirmation by call.

Training. Operation standard.

Basic education on self-disciplineand custom.

Training. Standard work.

Instructions on the job.Standard work

Total Productive M aintenance(TPM)Standard work

Basic training on discipline

～9:30

What are the worst 10 of POKA ?Careless-

ness

Misunder-

standingBrief look Novice Selfishness Dull-witted Irresponsi-

bility

Mal -

function

On purpose

1. Missing process

on work

2. Mistake of

process on work

3. Work set mistake

4. Missing parts

5. Mixing with

foreign parts

6. Wrong work

7. Mis-action of

machines

8. Mis-adjustment

9. Defective machine

10. Defective tools

and jigs

: Strongly related

: Related

Order

of causes

Types of

POKA

tytsys16.doc

-9:40

2. How to make POKA-YOKE ?1) Wares can’t be fixed to the jig in case of wrong work.

Sign and mark systemMake easy to detect byIndicating lamps or differentColor.

Jig systemGive ideas to jigs so thatwrong wares can’t be

fixed Or processing doesn’t start in case of

miss-fixing

Automatic systemA machine stops auto-Matically in case of wrong processing

2) A machine doesn’t start processing in case the wares is

something wrong.3) A machine doesn’t start processing in case of miss-work.

4) A machine proceeds processing after correcting miss –work

or miss-operation automatically.5) A following process checks the results of preceding process

and stop processing in case of wrong wares.

6) A following process doesn’t start in case there were

missing works.

～10:00

9:40--

これが基本的なまとめです。

Real Cause

4,10,12,16,17,20

4, 10, 17,18,19

4,5,6,10,12,17

11,12,13

5,6,10

5.6,11

5,10,16

5,6,7,9,10,14

5,6,10

3,4,8,10,12,15,17

3,15

1, 2,3

Mixing of foreign parts12Mistake of indication11Mistake of parts10Wrong setting of arrangement9

Mistake(2)

Missing parts8Mistake of operation7Missing Parts at assembly or processing6Missing Assembly or Processing5

Forget

Wrong amount in number4Wrong ( Foreign) Parts assembly3Wrong Work-set2Wrong Assembly or Processing1

Mistake(1)

Type of POKA

Type of POKA

Assembly of corrugated cartons and labeling are done by lot because of shipping information in mass.20

Indications, such as Labels and cases, are similar in size and color. 表示やケースの色やサイズが似ている19

Recording and counting of lot No. of indication is done by just memory. 暗記に頼って記録やカウントをする18

No fixed storage yard of parts and products. The amount is not constant and missing.置き場が決まっていない17

No system to stop the works in inner process when defective products happen.16

Operator does his job and takes parts at his convenience because no rule for stock yard. 勝手に部品選ぶ15

Difficult to detect missing parts and process because of so many parts and works.数が多く不足に気が付かない14

It is difficult to ascertain wrong or correct on size, amount and condition setting. 間違っても気が付きにくい13

Mistake of parts and material because of similar shape, size and color. 形、サイズ、色が似ている12

Operating conditions such as temperature, humidity, and pressure etc., differ. Then, mistake happens.環境11

The letters of indication or drawing are small or thin, therefore miss-reading takes place.字が小さく読みにくい10

No system to stop the work to flow to the next process in case of missing assembly or processing9

Only the person in charge knows parts and jigs storage yard. Then, helpers make mistake.特定の人のみ知る8

Operator does his job as he like and forgets オペレターの勝手7

Imperfect system of transfer of the job at the time of shift change. 作業交代時の引継ぎシステム不良6

No system for breaking away from the position at the time of rest, interruption and other job. 5

Mistake of reading because of similar name or number. 読み間違え4

Inverse setting of up/ down, right/left and inside/outside due to the similar or symmetrical shape. 同形3

The assembly or processing method depends on the judgment by operator オペレーターの判断任せ2

No system to stop the work to flow to the next process in case of wrong assembly or processing1

Real Cause of POKA

～10:30Break へ

-10:00Coffee Break

A defectiveproduct

POKA-YOKE

Stop

Control

Alarm

Alarm onoccurrence

Flow control

Stop onfailure

Detection on occurrence

( Happened ! )

Predictionfor occurrence( may happen ? )

Stop onabnormality

Control formisoperation

Predictionalarm

Situation

Devices

Mechanism of POKA-YOKE10:20-

Some hints on POKA-YOKEHint- 1: Method by Distinctive feature

1) by Weight Method

Set standard weight for an acceptedarticle and then detect defective oneby comparison with the standard

weight.The balance weight of left and rightcan also be applied for detection.

When a product is heavierthan standard weight, it stops.

!

2) by Dimension Method

Set standard by dimension such as length, height, thickness and diameter, and then detect defective one by comparison with the standard.

Stop!

Good product

Defective product

Nut

ベトナムのトンネル

?

3) by Shape Method

Set standard of correct article by making use of distinctive shapesuch as, hole, edge, projection,bend or quality of material, thendetect defective one by comparison with the standard.

Defective product

Good product

Next process

Selection armCorrect productDefective product

Hint- 2: Method by Sequence1) by Process Sequence Method

Make it impossible to continue successive operation, when combined motion of workers or machines does not follow standard.

Blanking Corner cutting Bending Welding

Stop !

Parts Box

Buzzer

Touching Sensor

2) by In- process Sequence MethodIn a certain process, when a worker did not follow a standard and missing work would happen, the following work could not be continued. ?

A B C D E F G H I

Each time a operator picks up part, each lamp turns off. When all parts from ‘A ’to ‘H’ are picked up, the aircylinder of ‘I’ is opened.

Until a part from ‘I’ is picked up, the air cylinder of ‘A’is closed.

1 2 3 4 5 1 2 3 4 5 6 7 8 9 106 7 8 9 10

11 12 13 14 1511 12 13 14 1516 17 18 19 2016 17 18 19 20

Prepare one set of parts in a box,and pick up one by one , assemblein numerical order.

Hint- 3: Method by Counting and Measuring

1) by Counter

In case the numbers, such as number of jobs or that of parts,is decided in advance, make the number as the standard thenalarm of the difference.

Failure !Correct

2) by Number of parts remained In case several sets, which consist of some parts, are being prepared, arrange corresponding number of parts by groupin advance first.Then, confirm wrong arrangement by the parts remained.

N pieces

N sets

PK-YK4.PPT

3) by Detecting Fix Number

Numbers, such as pressure, electric current, temperature ortime and so on, are fixed to control.When detected numbers are over the value, work or operationcan not be continued.

Air pressure, Temperature, Oil level, ThicknessElectric current, Voltage -----etc.

-10:40

Some examples of POKA-YOKE

Before KAIZEN After KAIZEN

Preventing wrong jig fixing at the time of jig change

Wrongproduct

long

short

body

upper jig A

lower jig A

lower jig B

upper jig B

Correctproduct

Correct Jig

Wrong Jig

PreventingPin and hole

Preventing a missing nut in weldingBefore KAIZEN After KAIZEN

Nut

Work

work

work

Nut

The work canbe welded

without a nut

Photo electric relay

Shield plate

Preventing to miss cooling water for high induction heating


Heating coil

Cooling watercock

Foot switchfor heating

Foot switch

Limit switch

Preventing missing and wrong calking


Missing calk in previous process

Wrong side calk inprevious process

Micro switch

Correct calk inprevious process

Examples of POKA-YOKE by the Type of Mistake

1. Missing Process on Work

Theme Mis-work for number of hole in drilling

Problem In case of drilling work, fixed number of holes is not kept then lack of holes takes place sometimes.


A operator makes hole by counting number.Then, mistake of number of hole happens.

A limit switch was attached to detect drilling andcount hole. Further more, another L/S was attachedto the fixing jig in order to detect setting of the work.When a worker takes out work with lack of number,a buzzer alarms.

Buzzer

Work

L/S forhole count

L/S for setting work

Jig

Correct workWrong work

2. Mistake of Process on Work

Theme Defect of hole in drilling

Problem In case of drilling work, an operator draws back the drill before enough penetration. This causes wrong holes and trouble in assembly process.

Before KAIZEN After KAIZENIt was decided in standard to let the drill go through,however, sometimes an operator draws the drill backbefore enough penetration. The operator judged the timing of drill draw-back by intuition. Thereforewrong holes were found sometimes in assembly.

A limit switch was attached to detect drilling andcount hole. Further more, another L/S was attachedto the fixing jig in order to detect setting of the work.When a worker takes out work with lack of number,a buzzer alarms.

BuzzerL/S1

L/S2

Confirmation switchfor starting drill

Confirmation switchfor penetration

3. Work Set Mistake

Theme Prevention of hole position mistake in drilling job

Problem In case of drilling work, an operator mistakes the setting and makes wrong drilling. This causes wrong holes and trouble in assembly process.


It takes place often to set a work inverted in drilling job. As a result, the position of holes are also inverted then it causes trouble in assembly process.

Groove in two sides of the work was utilized to detectcorrect setting. A limit switch was attached on the jigand then in case of wrong setting the machine did notstart operation.

Wrong work Correct workJig

L/S

4. Missing parts

Theme Prevention of missing insert parts in assembly process

Problem After die casting an insert part has to be attached, however, missing of thepart takes place often. In spite of total inspection by full-time inspector, the company still gets claims by customers for missing the parts.


A sensor was attached in bar removal pressing process after die casting to detect insert parts.In case insert was missing, the machine did notwork and at the same time buzzer made alarming.

Press

Cross sectionof the work

Insert parts

Die

Sensor

Insert part was often missing, and the work wassent to following process.

Missing !!

5. Mixing with foreign parts

Theme Prevention of attaching wrong parts in assembling process

Problem There are several change of products in type daily and workers sometimes attached wrong foreign parts.


A B C D

E F G H

I J K L

A

B C

D

E

F

GHI

J

K

L

I J K

A B C D

E F G H

LI J K

Rotating Rack

Parts ShelfRequest Panel

POKA-YOKE for Safety: How do you make POKA-YOKE?

Picture from: JISHA

11:15--

These are POKA-YOKE for Safety:Any more?

Picture from: JISHA

Exercise Sheet No. 1

Removing line connected

Your situation:You are a maintenance worker.You are removing electric line of electro- magnetic valve. Remember that there is a Control room of the line.

足踏み外し：パイプと格子間転倒：道具箱につまずく。感電：端子に触れる。工具落下：工具につまずく。

How do you foresee accidents?Make POKA-YOKE.

Picture from: JISHA

Exercise Sheet No.1

Tightening terminals

手の挟撃：風で扉閉まる｡足の挟撃：同上。胸の打撲：ドライバー滑る｡転倒：ケーブルに引っかけ｡

How do you foresee accidents?Make POKA-YOKE.

Picture from: JISHA

1. Let’s have flexible mind.2. Curiosity is the driving power of creativity.3. Make your own tools/methods for

developing idea.4. Concentrate to make idea (by hands)

then ideas will visit you.5. Be prepared to record ideas.6. Let’s be positive all ways.

Let’s be creative!!Takemura’s advice

Let’s have positive mind!

Xin cam on !

Hoping prosperity of your company,

VJCC is always ready to work with you.

Now let’s apply POKA-YOKE!!

Osborne Check List

Thíchứng

?

Sửa đổi ?

Phóngđại ?

Giảm thiểu ?

Thay thế?

Sắp xếp lại ?

Đảo ngược ?

Kết hợp ?

Dùng vào mục đích khác ?

SCAMPER: by Bob Ebare

Loại trừ ?

Adapt ?

Put to other uses ?

Modify ?

Magnify ?

Minify ?

Substitute ?

Eliminate ?

Rearrange ?

Reverse ?

Combine ?

Danh sách 7 Câu hỏi

C

+/

X

+ -

KAIZEN=VJCC

+ : thêm, mở rộng

-

X : nhân, kết hợp

: chia, tách

= : chuẩn hoá, dùng chung

C : loại bỏ, dừng

+/ : nghịch, đổi trật tự

: giảm, hạn chế, giới hạn

-

=

PhPhươươngng phpháápp đđốốii vvớớii Ý Ý ttưưởởngng

÷

÷

-

Methods for Productivity Improvement(Example)B

ig C

atego

ry

Improvement of Job MethodEfficient Man PowerElimination of Muda in MaterialImprovement of Operational Ratio

Improvement of Machine Efficiency

Good Quality with machineCapable Operator for machineProduction System for Small Lot

Reduction of WIPLayout ChangeSteps for layout improvementWhat is Unit ConsumptionProduction Cost by ProcessElimination of Muda in MaterialMaterial ChangeNew Idea for Product Development

Summary of Product Performance

Design with Cost Consciousness

Plan for Cost ReductionVariation of WIPTerm in ProcessClear Process ProgressStandard Process Schedule

P,CP,CCPPQP,CP,C,DC,DP,C,DP,C,DCCCCCCCCP,C,DC,DDD,C

I E

TPM

JIT

LayoutImpvmt

UnitConsu.Yield RatioVE/VA

DailyControlProductControl

Requirement( What do you want?)

Useful MethodM

iddl

eC

atego

ryC

atego

ry o

f

Resu

lt a

nd

Effect

Pro

cess

Ana

lysi

sT

ransp

ort

atio

nA

nal

Ope

ration

Ana

lysi

sM

otion A

nal

ysis

Tim

e A

naly

sis

6 b

ig L

oss

of M

achin

eA

uto

nom

ous

Mai

nte.

Pro

duct

ive

Mai

nte

.Q

ual

ity

Mai

nten

ance

PO

KA

-YO

KE

4M

in P

rodu

ctio

n3 E

lem

ents

in S

tandar

d

Lead

Tim

e R

edu

ction

Leve

ling

of

Pro

duction

KA

NB

AN

Sys

tem

JO

B C

ontr

ol Sys

tem

5S A

ctivi

ty

P-Q

Ana

lysi

s

VR

P M

ethod

QC

7 T

ools

New

QC

7 T

ools

FM

EA

Qual

ity

Audi

t Sys

tem

Pro

duction A

prova

lSys

Sta

tist

ical

Meth

od

Exp

erim

enta

l D

esi

gn

VE/V

A

Idea

Met

hod

Flo

w F

requ

ency

Char

tM

uda

Elim

inat

ion

Meth

od

Perf

orm

ance

Eva

luat

ion

Bre

ak E

ven P

oin

t A

nal

.

Pro

ductivi

ty Im

prove

ment

Cost

Redu

ction

Inve

nto

ry

☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆

☆ ☆☆ ☆

☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆

☆☆ ☆

☆ ☆ ☆ ☆ ☆ ☆ ☆☆☆

☆ ☆☆ ☆

☆

☆ ☆☆☆

☆☆☆ ☆ ☆ ☆

☆ ☆ ☆

☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆

☆ ☆ ☆ ☆ ☆ ☆ ☆☆ ☆ ☆ ☆☆ ☆ ☆

☆☆☆ ☆

☆

☆☆☆☆☆

☆

☆☆☆☆

☆

☆

☆

☆☆

☆

☆

☆☆

I E PM J I T

Note: P: ProductionC: CostD: Delivery

Note: P: ProductionC: CostD: Delivery

Pokayoke Treatment

Documents

Transcript of Pokayoke Treatment