5 Quality Maintenence

TPM Club India

Quality Maintenance Pillar

PILLAR Hinshitsu Hozen or Quality Maintenance 1  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

“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  Confederation of Indian Industry

© JIPM, 1994

2

TPM Club India

Quality Maintenance Pillar

Hinshitsu – Hozen Concept Caused by raw material conditions Producing materials and energy not to generate defects

Quality Defect Factors Caused by equipment Caused by method precision conditions

Manufacturing equipment not to generate defect

Devising methods not to generate defects

Quality Assurance + Equipment and environment management

PM Analysis

Design check

Fostering operators proficient in equipment and job

Jishu-Hozen activities +

Material Management

Skill Education and Training

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

Set conditions of generate defects

Caused by conditions of people involved

equipment

not

to

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

Management of conditions not to generate defects (Hinshitsu – Hozen)

Zero quality defects

 Confederation of Indian Industry

© JIPM, 1987

3

TPM Club India

Quality Maintenance Pillar

Relation among 5 Principles of TPM Development and Quality Maintenance Quality maintenance - Making of equipment which will not make poor quality products.



Individual Improvement

PM Analysis Basic Thinking of Improvement

Autonomous Maintenance Preventive Maintenance MP Design

Restoration Pursuit of the optimal Condition Elimination of Minor Defects Adjustments Clarification of Skill 7 Steps of Autonomous Maintenance

Setting of Conditions (Technical Aspect) Decide properly

Condition Control (Control Aspect) Observe precisely

• Daily Inspection • Proper Operation Application of Equipment Diagnosing Technology Feedback

Realization of

Education and Training

Zero-Defect

Fostering of personnel who thoroughly understand the equipment

4  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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 5  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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.  Confederation of Indian Industry

6

TPM Club India

Quality Maintenance Pillar

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  Confederation of Indian Industry

7

TPM Club India

Quality Maintenance Pillar

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 8  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Understanding quality defect phenomena

• Clarity on the definition of the defect • Frequency of occurrence and effect of defects

9  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Defects classification A - Type defect

B - Type defect

OK

OK NOT OK

NOT OK NOT OK

Action taken by operator

LSL

OK

C - Type defect

USL

• The output is (OK) initially • Becomes (NG) • Corrective action is taken by operator • Becomes (OK) • Uue Why – Why Analysis

No action by operator

LSL

OK

USL

• The output is (OK) initially • Becomes (NG) • No action taken by operator • Becomes (OK) • Use PM Analysis  Confederation of Indian Industry

Action taken by operator

OK

LSL

OK

USL

• The output is (NG) initially • Action taken by operator • Becomes (OK) (setting scrap) 10

TPM Club India

Quality Maintenance Pillar

A - Type defect : Examples OK

NOT OK

Action taken by operator

LSL

OK

USL

11  Confederation of Indian Industry

KAIZEN - SHEET Brakes Division

JiPm -TPM

Category: A

B

C

Providing

Sub Comm

CU

Changing

Kaizen Theme & Target :

QM

Before improvement:

Rejection Qty

Rejection Qty

EMA

Result / Benefit : Scrap due to wrong

8

6 4

4

SL. No.

Team MembersM . Karthikeyan 4

6

Year

2000- 01 CU 128

Machine No :

To eliminate process scrap due to Damage of M133551 Crank shaft Problem/Present Status :

Unit

3

loading

3

3

2

1

2

0

0

Nov'00

Dec'00

Jan'01

Jan'01

Analysis :

After improvement:

Component damage – Induction hardng

Inductor hitting the component POKA YOKE

Component loaded in the wrong direction

Why

Reversible

Ir-reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing

Why

Why

Kaizen type

Feb'01

Scope & plan for Horizontal Deployment SLNo.

1

M/cNo.

Target date

EMA

Mar’01

Resp.

Status

MK Compld.

Possibility of wrong loading

Root Cause: Idea :

Possibility of Wrong Loading

Prevent Possibility of Wrong Loading

Counter measure : Provide POKA YOKE

Poka Yoke type & Function

Shut Down

Prevention

Control

Detection

Warning

KAIZEN - SHEET Category: A

Brakes Division

JiPm -TPM

B

C

Providing

Kaizen Theme & Target :

Before improvement:

5

ACT

QM

3 2

1

1

2000- 01 AU 087 032505

4

4

2

3 2

2

2

1

1

0

0 June

July

Analysis :

Aug

Sep

Component damage during machining Why component pulled out Why Tennon broken

June

After improvement:

Why weaker section of the tennon Why Reduced thickness Why to avoid fouling with jaws Tennon fouling with the jaws Root Cause:

Idea :

Avoid tennon fouling with jaws

Counter measure : Change the jaw design and tennon thickness

SL. No.

Result / Benefit : 5

4

2

Year

Team Members N.Kothandaraman

Rejn Qty

Rejn Qty

4

Sub Comm

Machine No :

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

Problem/Present Status :

Changing

Unit

Kaizen type

July

Aug

Sep

0

0

Oct

Nov

Ir-reversible

Reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

01

M/cNo.

Target date

032507

Oct,00

Poka Yoke type & Function

Resp.

NKN

Status

completed

Shut Down

Prevention

Control

Detection

Warning

Unit

KAIZEN - SHEET Brakes Division

JiPm -TPM

Category: A

B

C

Providing

Changing

Kaizen Theme & Target : Eliminate process scrap due to damage in Un loader valve before Apr’00 Problem/Present Status : Process scrap due to Damage

Before improvement: ULV Body Wrong Side on the top

4

Sub Comm QM

V2

Year

SL. No.

2000 2001

V2 025

Machine No :

082501

Team Members

BDN / TSS

Result / Benefit : 4 3 Qty

2

2

2

2

1

Analysis : Damage in body Why ? Wrong loading of component Why ? Fixture accepting wrong loading Why ? No stopper arrangement to avoid wrong loading

After improvement:

Not able to load

Poka Yoke pin

0

0

Reversible

0

Ju l

M

Kaizen type

A pr

ar

b

Mar

Fe

'0 0

Feb

Ja n

Jan'00

ay

0

0 0

Ju n

1

M

Qty

3

Ir-reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

1

M/cNo.

Target date

086303

Aug’00

Resp.

Status

BDN completed

Root Cause:

No stopper arrangement to avoid wrong loading Provide stopper to avoid wrong Idea : loading Counter measure : Provide Poka yoke pin

Poka Yoke type & Function

Shut Down

Prevention

Control

Detection

Warning

TPM Club India

Quality Maintenance Pillar

B - Type defect : Examples OK

NOT OK

No action by operator

LSL

OK

USL

15  Confederation of Indian Industry

KAIZEN - SHEET Brakes Division

JiPm -TPM

Category: A

B

C

Providing

Changing

Kaizen Theme & Target :

Before improvement:

Problem/Present Status :

Process sequence

5 4

Mar

Apr

May

Aug ‘ 99

Au- 072

5 4 3 2

1

0

SL. No.

Result / Benefit :

Rough boring

2 1

Year

Team Members N.Kothandaraman

Facing , OD Turning & grooving

1

QM

Act

3

3

Sub Comm

Machine No : 032302

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

2

Unit

0

0

May

June

Finish boring July

Rough finish on bore After improvement: Process sequence Why ? Entrapment of Burr on bore during Facing , OD Turning & grooving finish boring operation . Why ? Rough boring Burr generated during Rough boring operation not fully flushed out Why ? Back facing Finish boring operation done immediately after rough boring operation . . Finish boring Process sequence Presence of burr during boring operation Root Cause:

Counter measure :

0

Back facing

Analysis :

Idea :

1

To eliminate burr presence Change process sequence

0

0

0

0

Aug

Sep

Oct

Nov

Kaizen type

Reversible

Ir-reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

01

M/cNo.

Target date

032304 Nov ‘ 99

Poka Yoke type & Function

Resp.

Status

NKN Completed

Shut Down

Prevention

Control

Detection

Warning

Unit

KAIZEN - SHEET Brakes Division

JiPm -TPM

Category: A

B

C

Providing

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

Machine No : Team Members

Before improvement:

SL. No.

2000 - 2001 CU -012

120802 M .Karthikeyan

4

Rejection Qty

Rejection Qty

Year

Result / Benefit :

High rejection ,while running the crank shaft without the tailstocks Support 4

4

QM

cu

Before Mar’2000

Kaizen Theme & Target :

Problem/Present Status :

Changing

Sub Comm

3 3

2

3

2

1

1 1

0

0

Mar'00

Apr'00

0

0 Dec'99

Jan'00

Feb'00

Analysis : High rejection in 120802 Why Tool digging Why Excess Runout in the component Why Component not located properly Why No tailstock clamping

Root Cause: Idea :

Kaizen type

After improvement:

Reversible

Ir-reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

1

M/cNo.

120801

Target date

Jul’00

Resp.

MK

Status

Completed

Tailstock not clamping Eliminate tailstock not clamping

Counter measure : Provide limit switch

Poka Yoke type & Function

Shut Down

Prevention

Control

Detection

Warning

TPM Club India

Quality Maintenance Pillar

C - Type defect : Examples NOT OK

Action taken by operator

OK

LSL

OK

USL

18  Confederation of Indian Industry

KAIZEN - SHEET Category: A

Brakes Division

JiPm -TPM

B

Providing

C

Unit

Sub Comm

cu

QM

Changing

Kaizen Theme & Target :

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

Problem/Present Status :

Before improvement:

Year

SL. No.

2000-2001 CU -185

Machine No :

087803

Team Members M .Karthikeyan Result / Benefit : 10

High process scrap due

Rejection Qty

8

to oil port spot face height undersize in M 134561 TCL crankcase

8

Before

After

6

6

4

4 2

0

0

Jan'01

Analysis :

Oil port Spot face height undersize Why? More material removed on face Why? Tool length set excess Why?

12.5

No Setting facility How? Provide Setting facility

Root Cause: Idea :

Kaizen type

After improvement:

Feb'01

Mar'01

Reversible

Apr'01

Ir-reversible

Setting Master If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

1

M/cNo.

086301

Target date

Jun’01

Resp.

MK

Status

Compl.

Tool length set excess Set the tool correctly

Counter measure :Provide Setting Master

Poka Yoke type & Function

Shut Down

Prevention

Control

Detection

Warning

KAIZEN - SHEET Brakes Division

JiPm -TPM

Category: A

B

C

Providing

Changing

Kaizen Theme & Target Eliminate : scrap due to Inner dia. O/S in

50 40

Sub Comm

v1

QM

Multi rotational dial gauge Before improvement:

28

10

3

8

4

1 7

2 6

40 Qt30 y 20

Big dial

5

20 0

10 Nov

Dec

34 28

0

10

Small dial

0

Nov

Jan’01 Feb

Analysis :

Kaizen type

After improvement: one rotational dial gauge

Dia 140.9 / 105.10 Bore over size 3

Wrong Setting by operator

4

5

2

6

1

7

Wrong reading of the dial Multi rotational dial Root Cause: Multi rotational dial gauge used for measurement the bore dial to one rotation type. Counter measureChange :

0

0

Dec Jan’01Feb’01Mar’01 Month Reversible

Ir-reversible

If reversible updated in Operation Standard / QCPC JH Check Sheet PM Check Sheet Eqpt / fixture Drawing Scope & plan for Horizontal Deployment SLNo.

multi rotational gauge IdeaEliminate :

2000-2001 v1 -168

50 Result / Benefit :

2

9

30

SL. No.

Team Members VT / RBS

34 1

Year

Machine No : 032601

R6 / RE6 top cover. Zero & Before March’01 Problem/Present Status :

Unit

1 2 3

M/cNo.

Target date

032504 Apr’01 032602 Apr’01 032201 Apr’01

Poka Yoke type & Function

Resp.

NKN RBS NKN

Status

Compl. Compl. Compl.

Shut Down

Prevention

Control

Detection

Warning

TPM Club India

Quality Maintenance Pillar

Setting of standard values for inspection items and confirmation of results 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. 21  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

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

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. 22  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

23  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

24  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

25  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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 Symbol 1 Loose Standard 2 No Standard 3As per standard and followed 4 Difficult to follow 5 Not followed 26  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

27  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

28  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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. 29  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Brakes India (Sholinghur)

30  Confederation of Indian Industry

TPM Club India

TPM MASTER PLAN QM SUB COMMITTEE

Quality Maintenance Pillar

31  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

MASTERPLANFORQUALITYMAINTENANCEACTIVITIES. Activity Palnned QM-STEPS 1. Preparationof QAMatrix:

Year Details of activity *Check qualitycharacteristics. *Investigatedefect modes and subprocess wheredefect occures. *Assess seriousness of defect mode.

2. Preparationof Production-Input conditionanalysis table

*Check deficiencyinproductioninput conditions for eachdefect modein eachsub-process. *Checkwhether standards exists andarebeing followed.

3.Preparationof problemchart

*Clearifyproduction-input conditions for problems ineachsubprocess. *Act promptlyagainst problems that canbetackledonthespot *Carefully workout countermeasures for complexproblems. *Devise in vrio estig as tio te ch ns iqu andssin plan *P ritie pn ro ble m be ysasse g

4.Evaluationof seriousnessof problems. (FMEA1)

*Investigateusingtechniques suchas P-Manalysis andpropose countermeasures.

8.Reviewof productioninput conditions.

*Reviewthe productioninput conditions identifiedin step2. *Check whether productioninput conditions are appropriate andcorrect. *Use the results of step8to summarize the inspectionitems. *Prepare quality checkpoint list.

10.Preparationof aquality component control table and asurance of qualitythrough

Actual line A

2004-2005

Q3

Q4

Actual line B

2005-2006

Q1

Q2

Q3

Actual Slitting

2006-2007

Q4

Q1

Q2

Q3

2007-2008

Q4

Q1

Q2

Q3

their impact onqualitydefects.

5. Usage of P-M analysistechnique totrackdown causesof problems. 6.Assesment of impact of proposedcounter measures (FMEA2). 7.Implementation of improvements.

9.Consolidation andconfirmation of all check points.

Actual Plant. A

*Performpreliminaryevaluationof the post improvement situation.

*Define standardinnumerical / observable form.

32  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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. 33  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Identification of Operating Conditions with respect to Machine, Material & Method Defect Sl.no Mode 1 Blister

Method (People) 1) Unloading of baked linings from Thermal shock oven in a specified time.

3M Relation Machine 1) Temperature in the Post curing oven as per the specification.

2) Variation in Setting of Vent stroke.

2) Curing pressure as per the specification.

Material 1) Moisture in the material 2) Variation in resin properties

3) Temperature in the curing mould as per specification.

2

Soft

1) Even spreading of mix in the moulds.

1) Curing pressure as per the specification.

2) Cleaning of mould edges after the application of Liquid emulsion solution in the moulds.

2) Temperature in the curing mould as per specification.

1) Inclined Plate Flow value of the powder resin as per specification. 2) Curetime of the resin as per specification. 3) Variation in the bulk density of the mix. 4) Concentration of the liquid emulsion solution as per specification.

According to standard Standards not properly followed

 Confederation of Indian Industry

Statndards needed

34

TPM Club India

Quality Maintenance Pillar

Identification of Operating Conditions with respect to Machine, Material & Method Sl.no 3

Defect Mode Dent

Method (People) 1) Cleaning of curing moulds after unloading the product.

3M Relation Machine 1) Chrome plating of the mould as per specification.

Material 1) Concentration of the liquid emulsion solution as per specification.

2) Temperature in the curing mould as per specification. 4

Crack

1) Setting of Vent stroke as needed to the product.

1) Temperature in the curing mould as per specification.

1) Variation in resin properties

2) Curing pressure as per the specification. 5

6

Flash Dent

Thickness Unclear

1) Cleaning of flashes in the edges of the box after unloading the lining from the curing moulds.

1) Clearance between the mould and the spacers

1) Weighment of mix as per the specification

1) Curing pressure as per the specification

2) Flash removal below the bottom mould.

2) Error free weighing scale at common weighing.

1) Inclined Plate Flow of the powder resin as per the specification

2) Curing pressure as per the specification. 1) Bulk density of the mix as per specification.

3) Correct stock removal in OD grinding. 4) Correct stock removal in ID grinding. According to standard Standards not properly followed

 Confederation of Indian Industry

Statndards needed

35

TPM Club India

Quality Maintenance Pillar

3M CONDITION FOR NO BLISTER BUBBLES 3M COndition

Required value

Machine

How to check

Responsibility

Frequency

Baffle plate

Both sheet should be seated Hand without gap

Comp.sup.

Daily

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

Digitron

Prod. Sup./operator Hourly

What to do

PROCESS Dipper temperature 28±2 C Latex circulation

No repelling of bubbles from Visual

Prod. Sup./Comp.sup Weekly

dipper agitator Drying

All teat end heaters should be switched off in I drier

Visual

Prod.Sup.

 Confederation of Indian Industry

Daily 36

TPM Club India

Quality Maintenance Pillar

3M CONDITION FOR NO BLISTER BUBBLES

3M Condition

Required value

No.1 product weight 0.75 - 0.80 Gms.

How to check

Responsibility

Frequency What to do

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

37  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

BILISTER BUBBLE -ANALYSIS S No. 1

2

Phenomenon Latex Temperature above 30°c

Former temp

Cause

Countermeasure

Chiller failure

Alarm provided

Solenoid failure

Alarm provided (K)

Voltage variation

Based on EB voltage

above 60°c. during II dipper

Tapping in Sub Station.

3

Dipper latex agitation.

Baffle plate misalignment.

4

Ammonia content above 0.5%

High Total Alkalinity

 Confederation of Indian Industry

Periodic check. Total Alkalinity checked once in a day and maintained below 0.5%.

38

TPM Club India

Quality Maintenance Pillar

GOOD IN NO GOOD -3 M CONDITION 3M conditions

Required value

Loading

Exactly on viton ring No gap

Solenoid wing gap

How to check

ResponsiFrequency bility

Visual

Supervisor

Every shift

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

Visual

Operator

Once in hour

Conductivity brush Voltage

No worn out layers

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

 Confederation of Indian Industry

What to do

39

TPM Club India

Quality Maintenance Pillar

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.  Confederation of Indian Industry

40

TPM Club India

Quality Maintenance Pillar

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. 41  Confederation of Indian Industry

TPM Club India

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

PHENOMENON

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

PHYSICAL VIEW LOGICAL REASONING

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

CONTRIBUTING CONDITION

01) Thrust exerted by Stitcher Disc is less.

-

02) Resistance given by tread is large.

RELEASING WITH 4M (PRIMARY)

RELATION WITH 4M (SECONDARY)

1.1) Air Leakage inside bellow.

1.1.1)Air Leakage from joints of Bellow. 1.1.2) Degraded Beloow

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

1.2.1) Air leakage from pipe joints. 1.2.2) Leakage from Pipe

1.3) Stitcher disc oblique transfer less thrust

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) Bottom Stitcher Play

1.4.1) Feed nut wear out 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 bar 1.5.2) Worm gear thread damage 1.5.3) Cylinder thread damage 1.5.4) Lead Screw thread damage

2.1) Tread Swells out near joint.

 Confederation of Indian Industry

2.1.1) Tread length more 2.1.2) Tread Splicing more

42

TPM Club India

Quality Maintenance Pillar

EVALUATION CHECK PART

01) Bellow

02) Air Pressure

03) Bush

04) Feed Nut & Gear

MEASURING METHOD

TOLERANCE

MEASUREMENT VALUE

-Air leakage from joint of bellow

-Visual / Hand

No leakage

No leakage

-Degraded Bellow

-Hardness

60-70 Shore-A

75

-Air leakage from pipe joints

-Visual / Hand

No leakage

No leakage

OK

-Air leakage from pipe . -Lever Bush wear out.

-Visual / Hand

No leakage

No leakage

OK

CHECK ITEM

Dimension Check ID-50±0.5 mm. ID-51 mm. (Vernier) OD-52±0.5 mm. OD-50mm.

W- 2 mm. -Pin Bush wear - Dimension Check ID-70±0.5 mm. (Vernier) out. OD-72±0.5 mm. W- 2 mm. -Housing Bush - Dimension Check ID-65±0.5 mm. (Vernier) wear out. OD-68±0.5 mm. W- 2 mm. -Feed nut wear out Dimension Check Pitch -10 TPI

W- 2 mm. ID-71 mm. OD-69mm. W- 2 mm. ID-65 mm. OD-68mm. W- 2 mm.

-Sprocket teeth damage

-Visual

Teeth damage

-Loose Coupling of Sprocket

-Visual

(Vernier)

No teeth damage No Looseness

10 TPI

Loose

 Confederation of Indian Industry

DECISION

OK Not ok

TROUBLE SHOOTING METHOD

RESULT

OK

OK

Bellow replaced

OK

OK

OK

OK

OK

To be Changed

Changed

OK

To be Changed

Changed

OK

OK

OK

OK

OK

OK

Not ok,To be Changed changed Tightened

Tightened

OK OK

OK

43

TPM Club India

Quality Maintenance Pillar

EVALUATION CHECK PART

CHECK ITEM

MEASURING METHOD

TOLERANCE

MEASUREMENT VALUE

-Visual

No looseness

Loose

05) Bottom Stitcher Height

-No locks of height adjustment square bar

06) WormGear

-Worm gear thread Dimension Check ID-76.2± 0.2mm. ID-75mm. (Vernier) damage Depth : 2 mm. Depth : 2 mm.

07) Cylinder

-Cylinder thread damage

DECISION

TROUBLE SHOOTING METHOD

Lock to be provided

Lock provided

Not ok, to be Changed changed

RESULT

OK

OK

Dimension Check OD-80.4± 0.2mm. OD-80.3mm. (Vernier)

OK

OK

OK

08)Lead Screw

-Lead screw thread Dimension Check OD-33.75± 0.2mm. OD-33.7mm. (Vernier) damage

OK

OK

OK

09)Tread

-Tread length more

1752

OK

OK

OK

- 3 mm.

OK

OK

OK

-Tread splicing more

Depth : 2 mm.

Measuring Tape

1750 ± 5 mm.

Dimension Check 0 mm. ± 3 mm. (Vernier)

Depth : 2 mm.

44  Confederation of Indian Industry

12

TPM Club India

Quality Maintenance Pillar

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

3 M C O N D IT IO N S C H E C K L IS T D e fe c t 3 M R e la tio n S l.n o M o d e M e th o d (P e o p le ) M a c h in e 1 N o tc h in 1g ) N o tc h in g o p e ra tio n to1 ) R ig id c la m p in g o f th e s ta rt a fte r c o rre c t b u ttin gp ro o f d u c t d u rin g n o tc h in g th e p ro d u c t o p e ra tio n .

M a te ria l

45  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Identification of Operating Conditions with respect to Machine, Material & Method 3 M FUGUAI IDENTIFICATION & RECTIFICATION Production Machine Problem

Defect Mode

inputs (3M) Method

Machine

Survey Method

NOTC HING

NOTCH ING

1) Notching operation starts before correct butting of the product

1) Clamping of the product is not rigid

Wrong Visual Location of Notching

Wrong Location Notching

Check air pressure in the gauge

Survey

Countermea sure

Result Limit switch fixing screw found loose and corrected

Air leak noticed at the pushing cylinder inlet due to damaged hose

 Confederation of Indian Industry

In charge

To check QM / the limit switch fixing pro condition du once in a cer week

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

Pr od uc er

46

TPM Club India

Quality Maintenance Pillar

PM Analysis Phenomenon

Wrong Location notching in TATA SCAM Products

Physically view (Logical reasoning) Product is shifted from it's Location during Notching operation.

Contributing Condition

1) Product is located without butting with the butting reference

Relation with 4M (Primary)

Relation with 4M (Secondary)

1-1) Pusher cylinder stroke length variation

1-1-1) Air pressure Low 1-1-2) Leak in the Cylinder seal 1-1-3) Disturbance to the limit switch setting 1-1-4) Dust accumulation in the guide bushes 1-1-5) Scoring marks in the guide rod 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

1-2) Premature clamping

1-2-1) Limit switch malfunction 1-2-2) Limit switch locking screw loose

A = Feeding Unit B = Holding Unit

Notching OK Lining

1-2-3) Less Clearance between the product and clamping band Not OK Lining 2) Product location change After clamping. Butting Reference

2-1) Variation in clamping force

Product

Notch cutters OK Condition

NOT OK Condition

 Confederation of Indian Industry

2-1-1) Band length is more 2-1-2) Air pressure low 2-1-3) Band locking screw got loosened 2-1-4) Burr between band and the product 2-1-5) Band Damage

47

TPM Club India

Quality Maintenance Pillar

PM Analysis Phenomenon

Physically view (Logical reasoning)

Contributing Condition

Relation with 4M

Relation with 4M

(Primary)

(Secondary)

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

48  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Review of Survey results Machine : Notching Machine, U-Line I

Phenomena : Wrong Location Notching Check Check Item Measurement Site Method Pushing 1.Air Pressure Pressure gauge Cyclinder2.Cylinder seal condition Visual 3.Air hose leak Visual 4.Leak in the ferrule Visual 5.Piston seal wear Visual 6.Dust accumulation in the guide bushVisual 7.Scoring marks in the ID of the guideVisual bush 8.Scoring marks in the guide rod Visual Limit 9.Limit switch function Visual switch 10.Locking screw loose Visual 11.Locking screw damage Visual Clamping12.Air pressure Pressure gauge Cylinder 13.Band Length Scale 14.Band Locking screw loose Visual 15.Burr in the band Visual 16.Band damage Visual 17.Clearance between the product and Vernier the band 18.Band elongation Scale 19.Band Fixing Hole elongation Vernier caliper 20.Cylinder fixing screw loose Visual 21.Cylinder fixing screw damage Visual Product 22.Thickness Micrometer 23.Burr in the ID surface Radius gauge

Evaluation Restoration / Standard Measured Value Value Improvement 4 - 7 bar 6 bar OK No damage No damage OK No Leak No Leak OK No Leak No Leak OK No damage No damage OK Free from dustFree from dustOK No scoring No scoring OK -

No scoring No Error Rigid Tight No damage 4 - 7 bar 380 +/- 3 mm No loose No burr No damage 4 - 6 mm

No scoring No Error Rigid Tight No damage 6 bar 386 mm No loose No burr No damage 9 mm

OK OK OK OK OK Not ok OK OK OK Not ok

No elongation No elongation No Loose No damage 16.72/17.12 0.127 proof

No elongation Elongated No Loose No damage 16.93 0.100 proof

OK Not ok OK OK OK OK

 Confederation of Indian Industry

Result

To replace band Clamping method To correct the modified bend in the band To relocate the hole -

49

TPM Club India

Quality Maintenance Pillar

Countermeasure for the causes identified Plant : TSK Plant II

SUNDARAM BRAKE LININGS LIMITED

KAIZEN IDEA - SHEET

Kaizen Theme :

Idea :

To eliminate wrong location Notching Scrap in U Line I

Problem / Present status

Counter Measure

Current Status

Clamping method modified

Target

Before

14 nos / Week Zero

Kaizen started on 07.01.2001 Kaizen finished on 08.01.2001 Team Members N. Sridhar R.Rajaambikeswaran Clamping Pad K.Venkatasubramanian K.Nambiappan Product G.K.Rajkumar

Notching area wrongly located in the product during notching operation. After

OK Lining Clamping band Notching

"B" TYPE PHENOMENA

To Improve the clamping grip of the lining.

Product

Benefits :

Fixture Not OK Lining

Wrong Location Notching scrap eliminated in U Line I Nothcing Machine Clamping Cylinders

Analysis :

Results:

Scope & Plan for Horizontal Deployment

Wrong location notching scrap in U-Line I S.No

After kaizen

28

1

15 0

0

0

0

0

Machine Target Chamfering 30.01.01 Machine

Resp

Status

UM

Completed

0

Sep2001

0

Jul-2001

0

May2001

0

Mar2001

9

Jan-2001

30 25 20 15 10 5 0

Nov'2000

Scrap in nos.

PM Analysis

Month

 Confederation of Indian Industry

50

TPM Club India

Quality Maintenance Pillar

51  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

52  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

53  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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. 54  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

ERRORS ARE INEVITABLE BUT CAN BE ELIMINATED

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 55  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

56  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

PREDICTION v/s DETECTION 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”. 57  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Example : Prevention 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)  Confederation of Indian Industry

58

TPM Club India

Quality Maintenance Pillar

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) 59

 Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

ALARM v/s SHUTDOWN v/s CONTROL ALARM Signals in form of buzzers, blinking lights are used to warn when an abnormality, has occurred (detect) / about to occur (predict). SHUTDOWN Normal function of machine or process is stopped when defect predicted/detected. CONTROL In 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 60  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

61  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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. PRESS

product JIG

3 (A)

CORRECT

PRESS

product

product

JIG

3 (B)

JIG

INCORRECT

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

After A limit switch turns the machine on only whenthe protruding neck is positioned where it is supposed to be . 62

 Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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.  Confederation of Indian Industry

63

TPM Club India

Quality Maintenance Pillar

MOTION STEP METHOD This 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

64  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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.)

65  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

66  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

J o b J o b

F ix tu re

F ix tu re

JOB WITHOUT THRU’ HOLE

Proximity

JOB WITH DRILLED THRU’ HOLE

67  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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 Gear

‘B’ InstalledWrongly

After OnlyGear ‘A’ CanBeInstalled

68  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Inspection Errors Section 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. Operator Leakag Seam sometimes e welded not sure of Testing jobs Done waiting leakage for testing test leakag e completion testing and keeps Before OK/Not kept OK Jobs without Leakage Test products in is kept in the OK tray on the the OK left. bin.

Head that stamps part number Advances when After it senses leakageadded Now Head forno stamping at leakage testing station. Only after leakage has been tested OK, job will be stamped by the Head for stamping

 Confederation of Indian Industry

69

TPM Club India

Quality Maintenance Pillar

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. 70  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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.

Nut Runn er

Nut

Picking

Proximity which senses picking of washer gives signal to Nut PICKING OF WASHER WILL BE SENSED TO Runner ALLOW THE START OF NUT RUNNER

Washer Sometimes missed

71  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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. 72  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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

RIGHT Notch to be made on the side with one hole

Movement of notch milling

WRONG Notch made on the side opposite to one hole

73  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

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.

Not possible to load

Fixture for Notch operation

74  Confederation of Indian Industry

TPM Club India

Quality Maintenance Pillar

Maintaining Zero Defect 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.  Confederation of Indian Industry

75

TPM Club India

Quality Maintenance Pillar

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.

76  Confederation of Indian Industry