22118440 5 Quality Maintenence

1

TPM Club India Quality Maintenance Pillar

Confederation of Indian Industry

Hinshitsu HozenHinshitsu Hozen

oror

Quality MaintenanceQuality Maintenance

PILLAR

2



“Hinshitsu-Hozen”What is “Hinshitsu-Hozen?

To maintain integrity of quality (state of 100% non-defectives)

* Condition setting :Set conditions for zero defects aimed at equipment and processes that do not produce quality defects.

* Daily and periodical inspections :Inspect and measure conditions in time series.

* Quality preventive maintenance :Prevent quality defects by maintaining measured values within the standard

* Trend control and predictive maintenance :Predict possibilities of quality defects occurring by observing trends of measured values.

* Prior countermeasures:Take measures beforehand

© JIPM, 1994

3



Producing materials and energy not to generate defects

Manufacturing equipment not to generate defect

Devising methods not to generate defects

Fostering operators proficient in equipment and job

Jishu-Hozen activities

Skill Education and Training

+

PM Analysis

Pursue relationship between quality characteristics and material and energy condition / equipment precision / method conditions

Maintenance and management ability training (Ability to find cause system troubles and to quickly and correctly take actions)

Set conditions of equipment not to generate defects

Management of conditions not to generate defects

(Hinshitsu – Hozen) Zero quality defects

Caused by raw material conditions

Caused by equipment precision

Caused by method conditions

Caused by conditions of people involved

Quality Defect Factors

Hinshitsu – Hozen Concept

© JIPM, 1987

Quality Assurance+

Equipment and environment management

Design checkMaterial Management

4



Quality maintenance - Making of equipment which will not make poor quality products.

Setting of Conditions (Technical Aspect) Decide

properlyRestorationPursuit of the optimal ConditionElimination of Minor DefectsAdjustmentsClarification of Skill

Individual Improvement

Autonomous Maintenance

MP Design

Education and Training

PM Analysis

Basic Thinking of Improvement

7 Steps of Autonomous Maintenance

• Daily Inspection• Proper Operation

Preventive Maintenance Application of Equipment Diagnosing Technology

Feedback

Condition Control (Control Aspect) Observe precisely

Realization of Zero-Defect

Fostering of personnel who thoroughly understand the equipment

<Coping with the TPM 5 Principles>

Relation among 5 Principles of TPM Development and Quality Maintenance

5



Concept of the Promotion of Quality Maintenance

To promote quality maintenance, it is necessary to satisfy the following two preconditions:• Forced machine deterioration has been thoroughly

removed.• Natural deterioration removal under is progresses.• Managers and operators have become skillful with

equipment, so that the functions and structure of equipment are well understood by them.

• Have Sufficient inspection skill. • Training of staff who handle equipment on skill.• Jishu-Hozen, Kobetsu-Kaizen, PM analysis training,

and skill education and training must be enforced

6



Choosing time of quality maintenance.

• Total Jishu Hozen Implementation.

• Workshop is free from forced deterioration.

•"when failures cannot be reduced, defects cannot be

reduced.”

• Losses such as Equipment failure, Minor Stoppages,

Process failure are under control.

•All relevant data on Quality defects is available.

7



Implementation Procedure for

Quality Maintenance

• Understanding quality defect phenomena.

• Setting of standard values for inspection items

and confirmation of results

• Concentration of inspection items and

shortening of inspection time

• Drafting of QM (Quality Maintenance) matrix

and reflection in standards

8



Implementation Procedure for

Quality Maintenance (contd…)

• Master plan for QM

• 3M Analysis

• PM analysis for exposure and handling of

malfunctions

• Kaizens and Poka Yoke for eliminating defects

• Maintaining Zero Defect

• Process capability improvement plan

9



Understanding quality defect phenomena

• Clarity on the definition of the defect

• Frequency of occurrence and effect of defects

10



Defects classification

A - Type defect B - Type defect C - Type defect

OK

OK

NOT OK

Action taken by operator

OK

OK

NOT OK

No action by operator

LSL USLLSL USL

OK

OK

NOT OK


LSL USL

• The output is (OK) initially• Becomes (NG)• Corrective action is taken

by operator• Becomes (OK)• Uue Why – Why Analysis

• The output is (OK) initially• Becomes (NG)• No action taken by

operator• Becomes (OK)• Use PM Analysis

• The output is (NG) initially• Action taken by operator• Becomes (OK) (setting scrap)

11



A - Type defect : Examples

OK

OK

NOT OK


LSL USL

Category:

KAIZEN - SHEET

Brakes Division JiPm -TPM

Kaizen Theme & Target :

Unit YearSub Comm SL. No.

Machine No :

Problem/Present Status :

Analysis :

Idea :

Scope & plan for Horizontal Deployment

Reversible Ir-reversible

If reversible updated inOperation Standard / QCPCJH Check SheetPM Check SheetEqpt / fixture Drawing

Poka Yoke type & Function

Prevention

Shut Down

Control

WarningDetection

SLNo. M/cNo. Status Target date Resp.

Kaizen type

Root Cause:

Providing Changing A B C

Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

To eliminate process scrap due to Damage of M133551 Crank shaft

6

4

3

0

2

4

6

8

Nov'00 Dec'00 Jan'01

Reje

cti

on

Qty

Possibility of Wrong Loading

Prevent Possibility of Wrong Loading

Provide POKA YOKE

3

0

1

2

3

4

Jan'01 Feb'01

Re

jec

tio

n Q

ty

M . Karthikeyan

Scrap due to wrong loading

EMA

POKA YOKE

2000- 01CU

Component damage – Induction hardng

Inductor hitting the component

Component loaded in the wrong direction

Possibility of wrong loading

Why

Why

Why

1 EMA Mar’01 MK Compld.

CU 128

Before improvement:

Operation Standard / QCPCJH Check SheetPM Check SheetEqpt / fixture Drawing

B CA

Eliminate process scrap due to Component pull out in M270081 Cylinder in machine 032505

4

1

2 2

0

1

2

3

4

5

June July Aug Sep

Rej

n Q

ty

Component damage during machining

component pulled out

Tennon broken

weaker section of the tennon

Reduced thickness

to avoid fouling with jaws

Tennon fouling with the jaws

Change the jaw design and tennon thickness

032507 Oct,00 NKN completed

4

1

2 2

000

1

2

3

4

5

June July Aug Sep Oct Nov

Rej

n Q

ty

N.Kothandaraman

Avoid tennon fouling with jaws

Why

Why

Why

Why

Why

032505

01

Category:

KAIZEN - SHEET




Machine No :

Problem/Present Status : Before improvement:

Analysis :

Idea :



If reversible updated in


Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:

Providing Changing

Counter measure :

Result / Benefit :

After improvement:

Team Members

QM 2000- 01ACT AU 087

Eliminate process scrap due to damage in Un loader valve before Apr’00

Process scrap due to Damage

Wrong loading of component

Damage in body Why ?

Why ?

Provide stopper to avoid wrong loadingProvide Poka yoke pin

BDN / TSS

1

3

2

0

2

4

Jan'00 Feb Mar

Qty

Fixture accepting wrong loading

Poka Yoke pin

ULV Body Wrong Side on the top

No stopper arrangement to avoid wrong loading

Why ?

No stopper arrangement to avoid wrong loading

1

3

2

0 0 0 00

2

4

Jan'0

0Feb M

arApr

May Ju

nJu

l

Qty

V2 2000 -2001

0863031 Aug’00 BDN completed

082501

Category:

KAIZEN - SHEET




Machine No :


Analysis :

Idea :





Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:


Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

Not able to load

V2 025

15



B - Type defect : Examples

OK

OK

NOT OK

No action by operator

LSL USL

Category:

KAIZEN - SHEET




Machine No :


Analysis :

Idea :





Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:


Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

To reduce process scrap due to rough finish onBore dia inM 272291 Ty 20 Ram

2

1 1

0 0

3

0

1

2

3

4

5

Mar Apr May May June July

0 0 0 00

1

2

3

4

5

Aug Sep Oct Nov

Entrapment of Burr on bore duringfinish boring operation .

Rough finish on boreWhy ?

Why ?Burr generated during Rough boringoperation not fully flushed out

Why ?

Finish boring operation done immediatelyafter rough boring operation . .

Process sequencePresence of burr during boring operation

To eliminate burr presence

Change process sequence

Process sequence

Facing , OD Turning & grooving

Rough boring

Finish boring

Back facing

Facing , OD Turning & grooving

Rough boring

Back facing

Process sequence

Completed Finish boring

032302

01 032304 Nov ‘ 99 NKN

Aug ‘ 99

N.Kothandaraman

Act Au- 072

Category:

KAIZEN - SHEET




Machine No :


Analysis :

Idea :





Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:


Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

To avoid the rejection in crank shaft due to tool digging mark

High rejection ,while running thecrank shaft without the tailstocks Support

4

3

1

0

1

2

3

4

Dec'99 Jan'00 Feb'00

Reje

cti

on

Qty

High rejection in 120802

Tool digging

Excess Runout in the component

Why

Why

0 00

1

2

3

4

Mar'00 Apr'00

Rej

ect

ion

Qty

Provide limit switch

Before Mar’2000

WhyComponent not located properly

M .Karthikeyan

2000 - 2001

Tailstock not clamping

cu

WhyNo tailstock clamping

Eliminate tailstock not clamping

120802

CU -012

1 120801 Jul’00 MK Completed

18



C - Type defect : Examples

OK

OK

NOT OK


LSL USL

Category:

KAIZEN - SHEET




Machine No :


Analysis :

Idea :





Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:


Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

12.5

Setting MasterOil port Spot face height undersize

More material removed on face

Tool length set excess

Why?

Why?

How?No Setting facility

Tool length set excess

High process scrap due tooil port spot face height undersize in M 134561 TCL crankcase

To reduce rejection due to Oil port spot face height undersize in TCL Crank case Zero by Apr’2001

8

6

4

00

2

4

6

8

10

Jan'01 Feb'01 Mar'01 Apr'01

Rej

ecti

on

Qty

Before After

087803

2000-2001

Set the tool correctly

Why?

Provide Setting facility

Provide Setting Master

M .Karthikeyan

cu CU -185

1 086301 Jun’01 MK Compl.

Category:

KAIZEN - SHEET




Machine No :


Analysis :

Idea :





Prevention

Shut Down

Control

WarningDetection


Kaizen type

Root Cause:


Counter measure :

Result / Benefit :

After improvement:

Team Members

QM

28

0 0

34

10

20

30

40

50

Nov Dec Jan’01 Feb

Multi rotational dial gauge

one rotational dial gauge

Month

10

20

30

40

50

28

0 0

34

Nov Dec Jan’01Feb’01Mar’01

0

Qty

Eliminate scrap due to Inner dia. O/S inR6 / RE6 top cover. Zero & Before March’01

Eliminate multi rotational gauge

Multi rotational dial gauge used for measurement

Dia 140.9 / 105.10 Bore over size

Wrong Setting by operator

Wrong reading of the dial

Multi rotational dial

VT / RBS

1 2

3

4

567

8

9

10

12

Small dial

Big dial

1

2

3 4 5

6

7

Change the bore dial to one rotation type.

032601

1 032504 Apr’01 NKN Compl.

2 032602 Apr’01 RBS Compl.

3 032201 Apr’01 NKN Compl.

2000-2001v1 v1 -168

21



If standard values are set for individual inspection items, and equipment

precision is maintained within the standard range, it is necessary to confirm

that all quality characteristics can be satisfied.

If they cannot, the cause is either that "there are omission in inspection items"

or "Standard values are not stringent enough." In either case, it is necessary to

return to PM analysis and carry out study.

Setting of standard values for inspection items and confirmation of results

22



If inspection items are many, inspection intervals are short, or inspection requires much time, maintenance and control will become difficult, and eventually achievement level will decline.

Elimination of forced deterioration and spots that are difficult to inspect depends greatly on Jishu-Hozen implementation.

Concentration of inspection items and shortening of inspection time

• Reducing inspection items by concentrating on the number of items for inspection

• Extending inspection interval by eliminating forced machine deterioration• Shortening inspection time by taking steps for 'difficult to inspect' spots

For orderly implementation of condition control, review inspection items themselves and satisfy the following conditions:

23



QA Matrix is prepared to establish the relationship

between defect / defect mode and the process which

causes it. It requires data collection for defects at various

process stages to prepare a QA Matrix.

Drafting of QM (Quality Maintenance) matrix and reflection in standards

24



25



26



3M condition analysis. Please follow following guidelines.

1 Based on QD matrix identify where the defect is generated

2 Draw a C & E diagram for the defect for each process/sub-process,

3 Identify inputs for each M (Man, Method, Machine and Material

4 Check each input whether Standard exists or not. If not then make a standard.

5 All standards are to be followed during Process.

6 If a standard is difficult to follow or if they are loose then standards are to be revised.

Status of Standard Symbol1 Loose Standard2 No Standard3As per standard and followed4 Difficult to follow5 Not followed

27



28



29



QM Master plan

Master Plan for quality maintenance is planning of various

activities in this pillar with respect to the time frame in

months and years. According to the stage of TPM

implementation it can start at various levels. In the

beginning it will start with data collection on defects to

improving conditions to sustaining zero defect conditions.

30



Brakes India (Sholinghur)

31



TPM MASTER PLAN QM SUB COMMITTEE

32



Activity Palnned Actual Plant. A Actual line A Actual line B Actual SlittingYear

QM-STEPS Details of activity Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3

9.Consolidation and confirmation of all check points.

*Use the results of step8 to summarize the inspection items. *Prepare quality check point list.

10.Preparation of a quality component control table and asurance of quality through

*Define standard in numerical / observable form.

7.Implementation of improvements.

8.Review of production input conditions.

*Review the production input conditions identified in step2. *Check whether production input conditions are appropriate and correct.

5. Usage of P-M analysis technique to track down causes of problems.

*Investigate using techniques such as P-M analysis and propose countermeasures.

6.Assesment of impact of proposed counter measures (FMEA2).

*Perform preliminary evaluation of the post improvement situation.

3.Preparation of problem chart

*Clearify production-input conditions for problems in each subprocess. *Act promptly against problems that can be tackled on the spot *Carefully work out countermeasures for complex problems. *Devise investigation techniques and plan 4.Evaluation of

seriousness of problems. (FMEA1)

*Priorities problems by assessing their impact on quality defects.

1. Preparation of QA Matrix:

*Check quality characteristics. *Investigate defect modes and subprocess where defect occures. *Assess seriousness of defect mode.

2. Preparation of Production-Input condition analysis table

*Check deficiency in production input conditions for each defect mode in each sub-process. *Check whether standards exists and are being followed.

MASTER PLAN FOR QUALITY MAINTENANCE ACTIVITIES.

2004-2005 2005-2006 2006-2007 2007-2008

33



3M analysis

This analysis is a set of conditions with respect to

machine, material and method for obtaining a good

products. It helps in identifying 3M standards and checking

is possible against these standards. Removing this

variability can some times eliminate Quality Defects in the

product.

34



Identification of Operating Conditions with respect to Machine, Material & Method

Defect Sl.no Mode1 Blister 1) Unloading of baked linings 1) Temperature in the 1) Moisture in the material

from Thermal shock oven in Post curing oven as pera specified time. the specification. 2) Variation in resin

properties2) Variation in Setting of Vent 2) Curing pressure as perstroke. the specification.

3) Temperature in the curingmould as per specification.

2 Soft 1) Even spreading of mix 1) Curing pressure as per 1) Inclined Plate Flow value in the moulds. the specification. of the powder resin as per

specification.2) Cleaning of mould edges 2) Temperature in the curingafter the application of Liquid mould as per specification. 2) Curetime of the resin as emulsion solution in the per specification.moulds.

3) Variation in the bulkdensity of the mix.

4) Concentration of the liquidemulsion solution as per specification.

According to standard Statndards needed

Standards not properly followed

Method (People) Machine Material3M Relation

35




Defect Sl.no Mode3 Dent 1) Cleaning of curing moulds 1) Chrome plating of the 1) Concentration of the liquid

after unloading the product. mould as per specification. emulsion solution as per specification.

2) Temperature in the curingmould as per specification.

4 Crack 1) Setting of Vent stroke as 1) Temperature in the curing 1) Variation in resin needed to the product. mould as per specification. properties

2) Curing pressure as perthe specification.

5 Flash 1) Cleaning of flashes in the 1) Clearance between the 1) Inclined Plate Flow of theDent edges of the box after mould and the spacers powder resin as per the

unloading the lining from the specificationcuring moulds. 2) Curing pressure as per

the specification.

6 Thickness 1) Weighment of mix as per 1) Curing pressure as per 1) Bulk density of the mix asUnclear the specification the specification per specification.

2) Flash removal below the 2) Error free weighing scalebottom mould. at common weighing.

3) Correct stock removal inOD grinding.

4) Correct stock removal inID grinding.

According to standard

Standards not properly followed Statndards needed

3M RelationMethod (People) Machine Material

36



3M CONDITION FOR NO BLISTER BUBBLES

How tocheck

Machine

Baffle plate Both sheet should be seated Hand Comp.sup. Daily

without gap

Dipper agitator Uniform Rotation Visual Prodn.sup Daily

Voltage 240±10 V Voltmeter Prodn.sup Daily

Track Chain No jerking Visual Prodn.sup Shift once

PROCESS

Dipper temperature 28±2 C Digitron Prod. Sup./operator Hourly

Latex circulation No repelling of bubbles from Visual Prod. Sup./Comp.sup Weekly

dipper agitator

Drying All teat end heaters should

Visual Prod.Sup. Dailybe switched off in I drier

Responsibility Frequency3M COndition Required value What to do

37



3M CONDITION FOR NO BLISTER BUBBLES

How to

check

No.1 product weight 0.75 - 0.80 Gms. Weighment Prodn.sup Hourly

Material(LATEX)

S.I.Value 2.0 - 2.4 S.I.check Comp.sup/Lab.sup Daily

Total alkalinity 0.35 - 0.50 % Titration Comp.sup/Lab.sup Daily

Sediments No sediments Hand Comp.sup/Lab.sup Weekly

3M Condition Required value Responsibility Frequency What to do

38



BILISTER BUBBLE -ANALYSIS

1 Latex Temperature Chiller failure Alarm providedabove 30°c

Solenoid failure Alarm provided (K)

2 Former temp Voltage variation Based on EB voltage

above 60°c. Tapping during II dipper in Sub Station.

3 Dipper latex Baffle plate Periodic check.agitation. misalignment.

4 Ammonia content High Total Alkalinity above 0.5% Total Alkalinity checked once in a day

and maintainedbelow 0.5%.

S No. Phenomenon Cause Countermeasure

39



GOOD IN NO GOOD -3 M CONDITIONHow to check

Loading Exactly on viton ring

Visual Supervisor Every shift

Solenoid wing gap

No gap Visual Operator Twice in a shift

Disc play No play Visual Operator Twice in a shift

stripping Uniform stripping Visual Operator Twice in a shift

Conductivity No worn out layers

Visual Operator Once in hourbrush

Voltage 1200/900V +100V Voltmeter Electrician Once in a shift

Carbon brush No powder Visual Fitter Once in a shift

Sensor LEDshould glow. Visual Electician Once in a shift

No product in helmet Visual Operator Twice in a shift

3M conditions Required valueResponsi-bility Frequency

What to do

40



Execution of PM analysis for exposure and handling of malfunctions

PM Analysis is one of the most effective techniques to handle B

type of problems. PM denotes (P) Physical phenomena (M)

Mechanism. In this analysis we try to establish the relationship

between phenomena and the physical mechanism behind it

which explain the contributing conditions to cause such physical

mechanisms. These contributing conditions are then elaborated

in terms of relationship with primary (man, material, machine,

method) conditions. Usually these primary conditions are not

measurable so they are once again converted into secondary

conditions that can usually be physically inspected against a

standard.

41



Execution of PM analysis for exposure and handling of malfunctions (contd…)

After finding the standards, a survey is performed to see

the variability against these standards and all such

conditions are listed as (Not Good). It is advisable to take

countermeasures against all these conditions

simultaneously so as to eliminate most of the chance

causes in the system. This helps achieving zero defects in

the product.

42



-

P.M. ANALYSIS ON ELIMINATION OF CURED PASSENGER TYRE SCRAP DUE TO TREAD BLOW

PHENOMENONCONTRIBUTING

CONDITIONRELEASING WITH

4M (PRIMARY)RELATION WITH 4M (SECONDARY)

1.1.1)Air Leakage from joints of Bellow.

1.2.1) Air leakage from pipe joints.

01) Thrust exerted by Stitcher Disc is less.

1.1) Air Leakage inside bellow. 1.1.2) Degraded Beloow

1.2) Required Air does not reach in bellow from air Hose.

1.3) Stitcher disc oblique transfer less thrust

1.2.2) Leakage from Pipe

1.3.1) Lever Bush Wear Out

1.3.2) Pin Bush Wear Out

1.3.3) Housing Bush Wear Out

1.3.4) Feed Nut Wear Out

1.3.5) Sprocket teeth Damage

1.3.6) Loose Coupling of Sprocket

1.4.1) Feed nut wear out1.4) Bottom Stitcher Play 1.4.2) Sprocket teeth damage

1.4.3) Loose coupling of Sprocket

1.5) Bottom Stitcher Height displacement

1.5.1) No locks of height adjustment square bar1.5.2) Worm gear thread damage

1.5.3) Cylinder thread damage1.5.4) Lead Screw thread damage

Air Entrapment between Nylon Carcass surface (A)and Rubber Tread bottom surface(B).

Force applied by Stitcher on Rubber Tread Surface is less than the resistance given by Rubber Tread.

PHYSICAL VIEW LOGICAL REASONING

02) Resistance given by tread is large.

2.1) Tread Swells out near joint.

2.1.1) Tread length more

2.1.2) Tread Splicing more

43



EVALUATION

CHECK PART DECISIONCHECK ITEM

01) Bellow -Air leakage from joint of bellow

MEASURING METHOD

-Visual / Hand

TOLERANCE

No leakage

MEASUREMENT VALUE

No leakage

TROUBLE SHOOTING

METHODRESULT

OKOKOK

-Degraded Bellow -Hardness 60-70 Shore-A 75 Not ok Bellow replaced

OK

OK

-Air leakage from pipe joints

02) Air Pressure

-Visual / Hand No leakage No leakage OK OK OK

-Air leakage from pipe .

-Visual / Hand No leakage No leakage OK OK

03) Bush -Lever Bush wear out.

Dimension Check(Vernier)

ID-50±0.5 mm.

OD-52±0.5 mm.

W- 2 mm.

ID-51 mm.

OD-50mm.

W- 2 mm.

To be Changed

Changed OK

-Pin Bush wear out.


ID-70±0.5 mm. ID-71 mm.-OD-72±0.5 mm.

W- 2 mm.

OD-69mm.

W- 2 mm.

To be Changed

Changed OK

-Housing Bush wear out.


ID-65±0.5 mm. ID-65 mm.-OD-68±0.5 mm.

W- 2 mm.

OD-68mm.

W- 2 mm.

OKOKOK

-Feed nut wear out04) Feed Nut & Gear

Pitch -10 TPI OK OK OK

-Sprocket teeth damage

-Visual No teeth damage

Not ok,To be changed

Changed OK

-Loose Coupling of Sprocket

-Visual No Looseness Loose Tightened OK


10 TPI

Teeth damage

Tightened

44



EVALUATION

CHECK PART DECISIONCHECK ITEM

05) Bottom Stitcher Height

-No locks of height adjustment square bar

MEASURING METHOD

-Visual

TOLERANCE

No looseness

MEASUREMENT VALUE

Loose

TROUBLE SHOOTING

METHODRESULT

OKLock to be provided

Lock provided

-Worm gear thread damage

06) WormGear

ID-76.2± 0.2mm. Not ok, to be changed

Changed OKDimension Check(Vernier) Depth : 2 mm.

ID-75mm.

Depth : 2 mm.

-Cylinder thread damage

07) Cylinder OD-80.4± 0.2mm. OKDimension Check(Vernier) Depth : 2 mm.

OD-80.3mm.

Depth : 2 mm.OKOK

-Lead screw thread damage

08)Lead Screw

OD-33.75± 0.2mm.OK


OD-33.7mm. OKOK

-Tread length more

09)Tread 1750 ± 5 mm. OKMeasuring Tape 1752 OKOK

-Tread splicing more


0 mm. ± 3 mm. - 3 mm. OK OK OK

12

45




3 M C O N D IT IO N S C H E C K L IS T

D e fe c t S l.n o M o d e1 N o tc h in g1 ) N o tc h in g o p e ra tio n to 1 ) R ig id c la m p in g o f th e

s ta rt a f te r c o rre c t b u tt in g o fp ro d u c t d u r in g n o tc h in gth e p ro d u c t o p e ra tio n .

3 M R e la tio nM e th o d (P e o p le ) M a c h in e M a te ria l

46




3 M FUGUAI IDENTIFICATION & RECTIFICATION

Production Machine Problem Defect Mode

Survey Survey Countermeasure In

inputs (3M) Method Result charge

Method NOTCHING

1) Notching operation starts before correct butting of the product

Wrong Visual Limit switch fixing To check the limit switch fixing condition once in a week

QM /

Location of

screw found looseproducer

Notchingand corrected

Machine NOTCHING

1) Clamping of the product is not rigid

Wrong Check air pressure

Air leak noticed Hose replaced & to ensure the hose condition during machine start.

Producer

Locationin the gauge

at the pushing

Notching cylinder inlet due todamaged hose

47



PM Analysis

Wrong Location Product is shifted from 1) Product is located 1-1) Pusher cylinder 1-1-1) Air pressure Low

notching in it's Location during without butting with stroke length variation 1-1-2) Leak in the Cylinder seal

TATA SCAM Notching operation. the butting reference 1-1-3) Disturbance to the

Products limit switch setting

1-1-4) Dust accumulation in

the guide bushes

1-1-5) Scoring marks in the

A = Feeding Unit guide rod

B = Holding Unit 1-1-6) Leak in the air hose

1-1-7) Scoring marks in the

ID surface of the guide bush.

1-1-8) Leak in the ferrule

1-1-9) Wear in the piston seal

Notching

OK Lining 1-2) Premature clamping 1-2-1) Limit switch malfunction

1-2-2) Limit switch locking

screw loose

1-2-3) Less Clearance between

the product and clamping band

Not OK Lining

2) Product location change 2-1) Variation in clamping 2-1-1) Band length is more

After clamping. force 2-1-2) Air pressure low

2-1-3) Band locking screw

got loosened

2-1-4) Burr between band and

Notch cutters the product

NOT OK 2-1-5) Band Damage

OK Condition Condition

(Logical reasoning) (Primary) (Secondary)

Phenomenon Physically view Contributing Condition Relation with 4M Relation with 4M

Butting

Reference

Product

48



PM Analysis

Wrong Location 2-1-6) Band elongation

notching in 2-1-7) Band fixing hole

TATA SCAM elongataion

Products 2-1-8) Burr in the ID surface

of the product

2-1-9) Clamping cylinder

fixing screw got loosened

2-1-10) Thickness of the

product is less

2-1-11) Clamping cylinder

fixing screw damage

(Logical reasoning) (Primary) (Secondary)

Phenomenon Physically view Relation with 4M Relation with 4MContributing Condition

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Review of Survey resultsPhenomena : Wrong Location Notching Machine : Notching Machine, U-Line I

Check Check Item Measurement Standard Measured Evaluation Restoration / ResultSite Method Value Value ImprovementPushing 1.Air Pressure Pressure gauge 4 - 7 bar 6 bar OKCyclinder2.Cylinder seal condition Visual No damage No damage OK -

3.Air hose leak Visual No Leak No Leak OK -4.Leak in the ferrule Visual No Leak No Leak OK -5.Piston seal wear Visual No damage No damage OK -6.Dust accumulation in the guide bushVisual Free from dustFree from dustOK -7.Scoring marks in the ID of the guideVisual No scoring No scoring OK -bush8.Scoring marks in the guide rod Visual No scoring No scoring OK -

Limit 9.Limit switch function Visual No Error No Error OK -switch 10.Locking screw loose Visual Rigid Tight Rigid Tight OK -

11.Locking screw damage Visual No damage No damage OK -Clamping 12.Air pressure Pressure gauge 4 - 7 bar 6 bar OK -Cylinder 13.Band Length Scale 380 +/- 3 mm 386 mm Not ok To replace band

14.Band Locking screw loose Visual No loose No loose OK -15.Burr in the band Visual No burr No burr OK - Clamping16.Band damage Visual No damage No damage OK - method 17.Clearance between the product andVernier 4 - 6 mm 9 mm Not ok To correct the modifiedthe band bend in the band18.Band elongation Scale No elongation No elongation OK -19.Band Fixing Hole elongation Vernier caliper No elongation Elongated Not ok To relocate the hole20.Cylinder fixing screw loose Visual No Loose No Loose OK -21.Cylinder fixing screw damage Visual No damage No damage OK -

Product 22.Thickness Micrometer 16.72/17.12 16.93 OK -23.Burr in the ID surface Radius gauge 0.127 proof 0.100 proof OK -

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Countermeasure for the causes identifiedPlant : TSK Plant II SUNDARAM BRAKE LININGS LIMITED

Kaizen Theme : Idea :

To eliminate wrong location Notching Scrap in U Line I To Improve the clamping grip of the lining. "B" TYPEPHENOMENA

Problem / Present status Current Status 14 nos / Week

Clamping method modified Target Zero

Notching area wrongly located in the Kaizen started on 07.01.2001product during notching operation. Kaizen finished on 08.01.2001

Before After Team MembersN. Sridhar

OK Lining R.Rajaambikeswaran

Clamping band Clamping Pad K.Venkatasubramanian

Notching Product K.NambiappanProduct G.K.Rajkumar

Fixture Benefits :Not OK Lining

Wrong Location Notching scrap eliminated in U Line I Nothcing Machine

Clamping Cylinders

Analysis : Results: Scope & Plan for Horizontal DeploymentWrong location notching scrap in U-Line I

PM Analysis S.No Machine Target Resp Status1 Chamfering 30.01.01 UM Completed

Machine

Counter Measure

KAIZEN IDEA - SHEET

28

915

0 0 0 0 0 0 0 0 005

1015202530

Nov

'200

0

Jan-

2001

Mar

-20

01

May

-20

01

Jul-2

001

Sep

-20

01

Month

Scr

ap in

no

s.

After kaizen

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52



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Poka Yoke for eliminating defects

To err is Human. Human Beings are very forgetful and tend to make mistakes. Many times we end up saying “Operator Carelessness / Negligence” or “Operator Inattentiveness”. If we carefully look at such processes, we can reason out that these are a combination of many factors rather than just “Operator Carelessness”.

Monotonous, mechanical and long tense working environment tend to make people commit mistakes. If we bracket these mistakes as “carelessness”, the people get demotivated and discouraged. Poka-Yoke is a technique for avoiding simple human errors at work.

Poka is a Japanese word meaning “inadvertent errors” and Yoke comes from Japanese word Yokerie meaning “to avoid”. This has also been termed as “Mistake / Fool Proofing” or “Fail Safing”. The idea behind poka-yoke is to free a person’s mind from maintaining repetitive vigil which may be practically infeasible. By doing so a person without the fear of making mistake can constructively do more value added activities.

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People always make mistakes. These can be reduced or

even eliminated. Some of the Poke-Yoke devices,

which can help avoid defects, are ;

• Guide Pins / Locators of different sizes.

• Error Detection Buzzers and Alarms

• Limit Switches, Proximity and Photosensors.

• Counters

• Checklists

ERRORS ARE INEVITABLE BUT CAN BE ELIMINATED

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BASIC CLASSIFICATIONS OF POKA-YOKE

• PREDICTION v/s DETECTION

• ALARM v/s SHUTDOWN v/s CONTROL

• CONTACT v/s FIXED VALUE v/s MOTION READING

METHODS

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When a Poka-Yoke is designed in a way that it helps the operator to recognise the defect before it is about to occur, it is called a Prevention or Prediction type Poka-Yoke.

When a Poka-yoke helps the operator to know immediately on the occurrence of the defect then it is called Detection type Poka-Yoke. Detection is “after’ the defect is produced. The merit of this type of poka-yoke is based on the stage at which the defect is detected. In simple language “Earlier the better”.

PREDICTION v/s DETECTION

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The figure 1-A shows that holes are wrongly drilled due to incorrect

positioning of plate.

Figure 1-B shows that incorrect positioning of the plate is prevented by

locating 4 reference pins. The cause of Incorrect Drilling (incorrect

positioning) is prevented.

Pins

Pins

1 (A) 1 (B)

Example : Prevention

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Example : Detection

Figure 2-A shows that plate with four holes drilled is to be despatched to

the Customer. Customer complaints show many plates with 3 holes

drilled.

Figure 2-B shows the mistake of less drilled holes is detected through a

check by using four locator pins on a gauge.

Pins

2 (A) 2 (B)

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ALARM v/s SHUTDOWN v/s CONTROL

ALARMSignals in form of buzzers, blinking lights are used to warn when an abnormality, has occurred (detect) / about to occur (predict).

SHUTDOWNNormal function of machine or process is stopped when defect predicted/detected.

CONTROLIn Prevention type Poka-Yoke , Control means that even intentional errors are impossible or methods by which the cause of a defect if starts happening, it is automatically prevented from happening (feedback mechanism).In Detection type Poka-Yoke , Control means that the process is not stopped but the defective items are automatically separated out and are not allowed to pass on to next stage

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CONTACT v/s FIXED VALUE v/s

MOTION READING METHODS

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CONTACT METHOD

These use the principle of physical or energy contact with the product using sensing devices. They range from guide pins, limit switches, photo electric beams, etc. Contact methods often take advantage of parts that are designed with an uneven shape. We can use guide pins or blocks that don’t allow the product to be seated in a machines jig in the wrong position.

product

JIG3 (B)

product product

JIG

PRESS PRESS

3 (A)

JIG

CORRECT INCORRECT

BeforeIn figure 3A the Sheet Metal Part could be placed incorrectly during forming operation

AfterA limit switch turns the machine on only whenthe protruding neck is positioned where it is supposed to be .

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FIXED VALUE METHOD

Fixed Value Methods are used when a fixed number of parts must be attached to the product or when fixed repeats of operations needs to be done at some process station. Counting devices count the number of times something is done and signals or releases the product from its clamping when the required number is reached.

E.g. Before

A tip of spot welding machine wears with use and should be replaced after certain number of welds. Operator used to forget changing the tip, resulting in defective product.

E.g. After

A counter, tracking the number of welds, stops the machine and flashes a light as a signal to change the tip.

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MOTION STEP METHODThis method senses whether a motion or step in the process has been carried out within a certain expected time ( of the machine cycle time)

This method uses sensors & devices like photoelectric switch connected to a timer.

E.g. A label dispensing machine uses a photoelectric switch to stop the line if it does not detect removal of label from the backing tape.

An example of the Motion Step Method for using Poka-Yoke

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TYPES OF SENSING DEVICES

We have many sensing devices:

• Limit switches, Micro-switches• Proximity Switches• Photoelectric Switches• Beam Sensors

• Sensor to detect changes in Physical condition like temperature, pressure etc. (Pressure switches, thermostats etc.)

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8 TYPES OF ERRORS

• Processing Errors including Safety Errors

• Assembly Errors

• Inspection Errors

• Processing Omissions

• Assembly Omissions

• Packing / Pasting / Labeling Errors

• Mis-orientation, Mis-alignment & Dimensional Errors

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Processing Errors including Safety Errors

Processing Error Section consists of examples where due to operators mistake some process step is partially or incorrectly done

For Example :

Sometimes the drill is raised back before drilling the required depth (through) . A Proximity Switch has been provided to sense the coming through of drill to indicate completion of drill operation

Fixture

Job

Fixture

Job

Proximity

JOB WITHOUT THRU’ HOLE JOB WITH DRILLED THRU’ HOLE

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Assembly Errors

This Section consists of examples where operator by mistake does partial or incorrect assembly.

For Example :

During Assembly of a gear on the shaft for two similar models, Gear ‘B” is assembled on the Shaft ‘a’ instead of Gear ‘A’. Gear A & B are similar looking gears differing only in the number of teeth.

To eliminate this error a Mating part is installed on the Assembly fixture corresponding to ‘A’ to ensure that only gear ‘A’ is loaded

Mating Part for A

Shaft ‘a’

Before After

Gear ‘B’ Installed Wrongly Only Gear ‘A’ Can Be Installed

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Inspection ErrorsSection on Inspection error consists of examples which are related to rejected components going down the line or to the customer. These errors are due to monotony and fatigue faced by the inspector.

The operator is not sure of the completion of leakage test and passes them to the bin meant for keeping jobs that have passed leakage test.

Seam welded jobs waiting for leakage testing

Leakage Testing Done

Beforekept

Jobs without Leakage Test is kept in the OK tray on the left.

Operator sometimes not sure of leakage testing test completion and keeps OK/Not OK products in the OK bin.

Head that stamps part numberAdvances when it senses no leakage

AfterNow Head for stamping added at leakage testing station. Only after leakage has been tested OK, job will be stamped by the Head for stamping

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Processing Omissions

This section consists of examples where due to mistake, the operator misses out few steps of the process

Example:

Four holes to be drilled Three holes drilled because of mistake

Now the drilling operation has been provided with counter and the job will not be unclamped unless, the counter with drilling machine reads four.

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Assembly Omissions

The section on Assembly Omissions consists of examples where an assembly part is not assembled by the operator by mistake and the assembly goes to next station.

For Example :

In an assembly operation washer were missed before providing nut. To remove this problem washer picking was sensed to give a start to nut runner.

Proximity which senses picking of washer gives signal to Nut Runner

Picking

Washer Sometimes missed

NutRunner

NutPICKING OF WASHER WILL BE SENSED TO

ALLOW THE START OF NUT RUNNER

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Packing / Pasting / Labeling Errors

As the name suggest this section includes examples on Errors in Packing / Pasting / Labeling.

For example:

On the cover page of this book an example of carton going without the medicine bottle inside is shown wherein due to mistake the packer missed to fill a bottle in the carton.

Now a draft of fan has been provided below the conveyor, carrying cartons with bottle, which is strong enough only to blow an empty carton.

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Mis-orientation, Mis-alignment & Dimensional Errors

This section consists of errors because of mis-aligned / mis-oriented job loaded on a process leading to slightly offset operations.

Example: Before

Movement of notch milling Movement of notch milling

RIGHT WRONG

Notch to be made on the side with one hole

Notch made on the side opposite to one hole

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Example: After

Now at notching operation the fixture has been made with 3 pins as shown. Job with wrong orientation cannot be loaded for Notch operation.

Fixture for Notch operation

Not possible to load

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There are lot of activities required to be done for

maintaining zero defects. It starts with following JH

checklist, preparing Quality Maintenance matrix,

preparing checklists for inspection of zero defect

conditions and also audits for monitoring activities related

to zero defects. This involves preparing correct operating

standards and other standards for maintenance.

Maintaining Zero Defect

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Process Capability Improvement Plan

Sometimes capability of a process needs to be enhanced

to obtain high Cp value for critical characteristics. This plant

again follows the analysis for variation in the characteristics

and taking countermeasure against all the sources.

22118440 5 Quality Maintenence

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Transcript of 22118440 5 Quality Maintenence