2013 - 7qc story- brakes team - front pad worn out in sumo

Copyright, Confidential, Tata Motors Ltd

Team: Brake System

7 Step QC story

7 Step QC storyProblem Solving Methodology

SUMO Front Brake pad worn out


Review with Mentor - Mr G R Nagbushan

Review with Champion - Mr Suyog panse

Review with Team Leader - Mr Bisen Badal

Team Charter

Team Leader - Mr.Bisen Badal

Co - Leader - Mr. Ramani K.R

Team Members -

Mr. Jagdish G Naganoor, Mr.K.Pavan, Mr.Karadi S.B, Mr.Gharat .R.V,

Mr.Kulkarni S.G, Mr Mhaske, Mr Deshpande.R, Mr Patil suhas,Mr

Diwakar.R, Mr Satyajit Patil.

Review Mechanism

Target

(6Monthly IPTV- May12

Production Batch)

SUMO GOLD

ModelCurrent Status

(6Monthly IPTV- Aug 12

Production Batch)

0.66+1.99

Training Needs

Goal Structure

# Warranty reduction of Brake judder/ Pad worn out- issue

resolution by structured problem solving methodology

# Developing Detection Strategy throughout manufacturing

and inspection process

# Updating Design Guideline, DFMEA, DVP, RFQ and

Process Documents based on Failure Mode Analysis and

Permanent Corrective Actions

Target

0

0

0

0


Step: 1 Define Project: Team Charter & Goal Statement



Step: 1 Define Project: Team Charter & Goal Statement

CFT STRUCTURE- Define Roles & Responsibility

Aggregates : Brakes Project Front brake pad worn out/ Defective

Mentor : Champion: Bisen Badal

SR No Team member Contact no Role Department

1 Mr. Gharat.R.V 8149059178 QA

2 Mr. Kulkarni.S.G QA

3 Mr. Mhaske QA

4 Mr. Karadi.S.B 7276045242 ADD

5 Mr. Deshpande.R APL

6 Mr. Jagdish G.N ERC

7 Mr. Pavan.K 8149095987 ERC

8 Mr. Asnikar.G 9881509735 ERC

9 Mr. Suhas Patil Mfg

10 Mr. Diwakar.R Mfg

11 Mr. Satyajit Patil Six Sigma



Step: 1 Define Project: Action Planner

Action planner 2013

Feb March April May

Project : Brake Pad worn out 4 5 6 7 11 12 13 14 15 18 19 20 21 25 26 27 28 29

PLA

N

Team Charter CFT formation Plan

Act

GOAL Statement Target Definition Plan

Act

Data Collection Warranty / JD/ CC DVP/ DFMEA/ Standards / PFMEA/ SOP/WI

Plan

Act

Data Stratification Multi level paritoPlan

Act

Failed part s analysis

On test rig/ Vehicle analysis (Min 30 failed parts

Plan

Act

Problem Definition Focused issue to be worked upon

Plan

Act

Deeper Analysis Why- Why / 5W-2H analysis Plan

Act

Bench marking Competitor products/ Process benchmark (min 3)

Plan

Act

Cause Effect Analysis

Ishakawa Diagram Plan

Act

Plan Action Progress



Step: 1 Define Project: Action Planner

Action planner 2013

FEB MARCH APRIL MAY

Project : Brake Pad worn out 4 5 6 7 11 12 13 14 15 18 19 20 21 25 26 27 28 29

DO

ContainmentAction

Interim Corrective Action

Plan

Act

Verification & Validation of causes

3G Analysis

Plan

Act

Root cause analysis 7QC tool and 8D methodology

Plan

Act

Verification & Validation

Sample batch tryout Plan

Act

ActionImplementation

Permanent corrective action

Plan

Act

Ch

eck

Check Results Warranty / JDP/ Customer complaints

Plan

Act

Act

ion

Recurrence prevention

Capture the learning & documents DFMEA, PFMEA , Design rule, Control plant/ WI

Plan

Act

Standardization Horizontal deployment Plan

Act

Felicitation Plan

Act

Plan Action Progress



Step: 1 Define Project: Bird Eye view

Fie

ld IP

TV

In P

rocess

FY10-11 FY12-13FY11-12

In-H

ou

se R

eS

up

pli

er

EO

L

FSO Not Ok at TML for assly run out (nos)

0 0 0 0 03

0

13

0 0 0 0 0

0

25

50

75

Jan-

11

Feb-

11

Mar

-11

Apr-1

1

May

-11

Jun-

11

Jul-1

1

Aug-

11

Sep-

11

Oct-1

1

Nov-11

Dec-11

Jan-

12

nos

Brake disc Primary Rejection VQA( nos)

0 0 0 0 0 0 0 0 0 0 0

29

0

25

50

75

Jan-

11

Feb-

11

Mar

-11

Apr-1

1

May

-11

Jun-

11

Jul-1

1

Aug-

11

Sep-

11

Oct

-11

Nov-

11

Dec-

11

nos

No data available

Take away: Detection adequate at Process, incoming stage for brake disc and hub defects.No failure of wheel cylinder at assly stage.

Bird Eye View

Brake disc Primary Rejection VQA( nos)

04

10

0 05

0 0 0 0 0 0 0

0

25

50

75

Jan-

12

Feb-

12

Mar

-12

Apr

-12

May

-12

Jun-

12

Jul-1

2

Aug

-12

Sep

-12

Oct

-12

Nov

-12

Dec

-12

Jan-

13

nos

Data not available

Supplier Data Not Available for

brake pad, caliper defects

FSO Not Ok at TML for assly run out (nos)

0 0 0 0 03

0

10

30 1

40

0

25

50

75

Jan-

12

Feb-

12

Mar

-12

Apr

-12

May

-12

Jun-

12

Jul-1

2

Aug

-12

Sep-

12

Oct

-12

Nov

-12

Dec

-12

Jan-

13

nos

Data not available Data not available


5.98

1.99

1.33

0.66 0.66 0.66

53%

71%

82%88%

94%100%

0

1

2

3

4

5

6

7

REAR

WHEEL

CYLINDER

BRAKE

DISC

VACUUM

BOOSTER

BRAKE

FIEXIBLE

HOSE

BRK

LINERS

CALIPER

PAD

Compl Description

IPT

V

0%

20%

40%

60%

80%

100%

120%

40

20

14

14

12

11

9 7

5 5

2 1 1

29%

43%

53%

63% 71% 80% 86%

91%

94%

97%

99%

99%

100%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5

10

15

20

25

30

35

40

45

Ele

ctr

ica

ls

Ca

b

Clu

tch

En

gin

e

En

gin

e e

lec

tric

als

Bra

ke

s

HV

AC

Ste

eri

ng

Su

sp

en

sio

n

Ax

le

Co

oli

ng

Ch

as

sis

Ge

ar

bo

x

Pe

rce

nta

ge

Cm

pls

(IP

TV

)

Aggregates


Step: 2 : Observation:2.0- Data Collection

Sumo

Model level IPTV 141

Brakes 6M IPTV 11

% Contribution 8%

98

6

23

8

19

3 1 4

5

1 2

4 6 3 4 1 3 2 1 0 2 2

106

15

34

20 2

4

12

6 7 8 9

10

4

11

9

18

33

18

25

15

26

19 22

20

17

26

16

11

11

122

33

59

29

43

41

10

28

25

23 2

8

18

53

64

56 6

2

60 6

6

41

77

69

65

124

38

70

35

54 5

9

16

39

30 31 32

23

66

75

71

70

124

40

73

37

5761

21

41

3331

0

20

40

60

80

100

120

140

May/1

0

Ju

n/1

0

Jul/10

Aug/1

0

Sep/1

0

Oct/

10

Nov/1

0

Dec/1

0

Ja

n/1

1

Feb/1

1

Mar/

11

Apr/

11

May/1

1

Ju

n/1

1

Jul/11

Aug

/11

Sep/1

1

Oct/

11

Nov/1

1

Dec/1

1

Ja

n/1

2

Feb/1

2

Ma

r/1

2

Apr/

12

May/1

2

Ju

n/1

2

Jul/12

Aug/1

2

Sep/1

2

Oct/

12

Cm

pls

/ 1

000

3 mth 6 mth 12 mth 18 mth 24 mth

Brake Aggregate Graph



JAN FEB MAR APR MAY JUNE JULY AUG

No of vehicle produced 3058 2890 2982 3221 3564 2393 1506 2979

No of complaints 58 65 61 55 93 39 17 33

0

50

100

150

200

0

500

1000

1500

2000

2500

3000

3500

4000

No

of

Co

nce

rns

No

of

veh

icle

pro

du

ced

Model Wise Production Vs Reported Complaints (Brake Aggregates) Period - JAN 12 To AUG 12

19

22

17

20

26

16

11

11


Brake complaints shows down trend after June batch production by approx 40%

Production Batch

6-Monthly IPTV

Brake pedal hole tolerance revised on NOV -11

Stop light switch gap adjustment gauge introduced at TCF

Corrective Action Implemented

Gap checking gauge introduced at final inspection



Wheel cylinder leak/Sc

ored

Brake disc

runout/ uneven contact

Brake vacuum booster

all defects

Caliper pad

worn/ Crack

Caliper assy all defects

Brake liners worn/

cracked

Parking brake cable defect

Brake master

cyl leak/ Scored

Brake drum

scored/ uneven contact

Brake pipe

crack/ Leak

Brake line

connectors leak

Brake Hose

crack/ Leak

ABS all defects

LCRV Defectiv

e

Hand brake lever knob

broken

Brake fluid

container/ leak

No of complaints 314 276 112 71 50 44 43 24 23 17 8 7 6 3 2 2

cum % Age 31 59 70 77 82 86 90 92 94 95 96 97 98 99 100

31

59

70

7782

8690 92

94 95 9697 98 99

100

0

20

40

60

80

100

120

0

50

100

150

200

250

300

350

Cu

m %

Age

No

of

veh

icle

pro

du

ced

SUMO BRAKE COMPLAINTS RECEIVED DEFECT WISEPeriod - JAN 12 To AUG 12 production batch


Top Four Brake complaints contributes 77% of total brake aggregates complaints .



JAN FEB MAR APR MAY JUNE JULY AUG

VEHICLE PR 3058 2890 2982 3221 3564 2393 1506 2979

No of complaints 11 12 10 10 19 3 1 5

0

500

1000

1500

2000

2500

3000

3500

4000

0

5

10

15

20

No

of

Ve

hic

le p

rod

uce

d

No

of

Co

mp

lain

ts

Front Brake pad Worn out Monthly IPTVPeriod - JAN 12 To AUG 12

3.54.1 3.3

3.15.3

1.2

0.6

3.5

NORTH SOUTH WEST EAST

No of complaints 37 16 11 6

% Age 53 72 95 100

53

72

95100

0

20

40

60

80

100

0

10

20

30

40

%A

ge

No

of

Co

mp

lain

ts

Front Brake pad Worn out Region WisePeriod - JAN 12 To AUG 12

Delhi Bangalo

rePune

Deharadun

Bijapur Mumbai Others

No of complaints 29 13 9 3 2 2 10

% Age 43 62 75 79 82 85 100

43

62

75 7982 85

100

0

20

40

60

80

100

0

5

10

15

20

25

30

35

%A

ge

No

of

Co

mp

lain

ts

Front Brake pad Worn out City WisePeriod - JAN 12 To AUG 12

> 5K 5K-10K 10k-15K 15K - 20K

No of complaints 12 9 33 18

0

5

10

15

20

25

30

35

No

of

Co

mp

lain

ts

Front Brake pad Worn out Kms WisePeriod - JAN 12 To AUG 12

Step: 2 : Observation:2.1- Data Collection: Front brake pad worn out

Pad worn out trend is similar to overall brake aggregates trend .

75 % of Pad worn out cases are reported from dense city traffic condition.


Step: 2 : Observation:2.1- Data Collection :: Front brake pad worn out


Matrix Chart

Brake pad Defective

Brake pad hard/ Glazed

Brake Pad worn out

UnevenWear Total % Age

Brake Grabbing 1 3 4 5%

Brake Hard 1 1 2 3%

Brake Insufficient 4 3 10 2 19 27%

Brake Jam 3 1 4 6%

Brake Noisy 3 25 2 31 44%

Brake shuddering 11 11 15%

Grand total 5 7 53 5 71 100%

% Age 7% 10% 76% 7% 100%

Dealer

Analysis

Customer

Verbatim

86 % Customer has reported Brake noisy , Brake insufficient & Brake Shuddering due to front brake

pad worn out.

76 % of complaints found that the friction material was completely worn out .

PCR data received from Jan 12- Aug-12



Matrix Chart

Brake pad Hard/ Glazed

Brake Pad worn out

Total % Age

Brake Pad Defective 15 15 48%

Brake Pad Hard/ Glazed 2 2 4 13%

Brake Pad Worn out 9 9 29%

Uneven Wear 3 3 10%

Grand total 2 29 31 100%

% Age 6% 94% 100%

Failure

Mode

Dealer

Analysis

Step: 2 : Observation:2.1- Data Collection :: Front brake pad worn out

94 % of complaints reported found that the friction material was completely worn out .

Material Receipt at TML & Investigated


Step: 2 : Observation:2.2- Under Standing


Process documents, drawings, Control Plans, WIS, DVP, DFMEA, Design Guideline

Dealer

AnalysisDESIGN CONTROLS

Sl No Design Control Activity Document

1 Front Caliper/ Brake pad Part Drawing Release

2 Information Fitment Drawings

3 Design Validation Plan (DVP)

4 DFMEA

5 Test Specifications (TS)

6 Service Advisory

7

8


Step: 2 : Observation:2.3- Failed part Analysis


Visual / On Test Rig / Vehicle analysis (Minimum 30 failed parts)

Dealer

Analysis

Test on

Vehicle

Friction material property analysis

Pass

Critical parameters Measurements

Root cause Identification

Visual Inspection

Feedback to dealer through CS

Trials with

customer

support

Fail

Pass

Testing

on Test

rig

Fail

GAP ANALYSIS

Simulating testing

methods with Actual

customer usage.

DVP up-dation.

Identifying new test

methodology

OK

NOT OK

OK



Brake pad defectiveBrake pad hard/ GlazedBrake pads worn out Uneven wear

Dealer Analysis 15 4 9 3

0

2

4

6

8

10

12

14

16

Nu

mb

er

of

com

pla

ints

Level-1 Pareto for Pad worn out -Front

Pads wornout

Concern observations 15

0

2

4

6

8

10

12

14

16

Nu

mb

er

of

com

pla

ints

Level-2 Pareto for Brake Pad Defective

Brake pad hard/ Glazed

Brake pad worn out

Concern observations 2 2

0

1

2

3

4

5

6

Nu

mb

er o

f co

mp

lain

ts

Level-2 Pareto for Brake Pad Hard / Glazed

Pads worn out

Concern observations 12

0

2

4

6

8

10

12

14

Nu

mb

er o

f co

mp

lain

ts

Level-2 Pareto for Brake pads Worn out & Uneven wear

Step: 2 : Observation:2.3- Failed part Analysis

29 number of incidents analyzed and found that friction material was completely worn out .

Total number of complaint investigated - 31



Step: 2 : Observation:2.5- Problem Definition

Brake pad Worn out

Brake

Grabbing

Brake Pad Defective

Brake pad

worn out

Brake

Hard

Brake pad

Hard/Glazed

Brake pad

Worn out

Brake insufficient

Brake pad

Defective

Brake pad

Hard/Glazed

Brake pad

Worn out

Uneven

wear

Brake Jam

Brake pad

Worn out

Uneven

wear

Brake

Noisy

Brake pad

Hard/ Glazed

Brake pad

Worn out

Uneven

Wear

Brake Shuddering

Brake pad

Worn out

Brake pad

Worn out

Brake pad

Hard/Glazed

94% 6%

4 2 19 4 31 11

94% of complaint found that friction material on front brake pad was completely worn out .



Pedal box Assembly

Stop light switch

Brake pedal

Booster Assembly

Knuckle assembly

Disc

Caliper

Step: 2 : Observation:3- Understanding design, mechanism and functionality, benchmarking comparison at concept level

Stop light switch gap

adjustment



Front brake

pad worn out

Aggregates Un cleaned

SUPPLIER

Brake pad inconsistence

properties

Lack of 100% Roll back inspection

Pads fitted in reverse direction

TML

Brake fluid contamination

Brake light switch improper adjustment

High lateral hub play

Skip or improper knuckle

assembly critical

parameter, DTV/ Run-out

Clevis pin tight

Step: 3 : ANALYSIS : 3.0- CAUSE EFFECT ANALYSIS Ishikawa Diagram for each defect

Low roll back

Knuckle

Caliper

DISC/DRUM

Brake pedal Assembly

Pedal pivot point tight

Brake light switch

improper adjustment

Clevis hole/pin tight

Brake Booster Assembly

TMC cutoff port blocked

Firewall deflection

TMC seal swell

Excess out put rod setting

High standout setting

Sluggish return

Caliper mount improper parallelism

Caliper mount offset

Sliding pin bend/ Jam

Poor Surface finish

High DTV / Run out

Environment Condition

Rainy

Excessive dust / Sand.

Coastal Area

brake servicing at Un authorized

service centers

Service

Usage of non genuine spare parts

Vehicle Overloading

Customer Usage

Rim/Tire modifications

High traffic/ Hilly terrain

TAXI/ Personnel

Knuckle

Brake system

Improper pad selection

Improper brake distribution

Caliper mount offset specification

HUB

Higher Run-out value

Higher surface finish value

Brake fluid

Improper grade selection

Brake Pads

High wear rate

Higher caliper roll back



Step: 3 : Analysis : Cause & Effect Matrix




Analysis results- Summary

CALIPER PAD WORN OUT/FRONT (KC 42011)

1 Improper Stop light switch adjustment.

2 High residual drag on BIL caliper 75Kgcm, due to mue-set shims.

3 Brake pedal sluggish due to tight tolerances of clevis pin & pedal hole.

4 Appache 522/12 friction material inconsistence in performance. Poor performance & wear characteristics in City & Hilly region application




Action plan - Summary

CALIPER PAD WORN OUT/FRONT (KC 42011)

1

Brake stop light switch adjustment with designed gap gauge implemented on production line from March-2012.

As a Poke-Yoke new snap-on type brake stop light switch is designed. Implementation planned from March -2013.

2

Mass added caliper (C57), is under validation with Wolverine shim with target residual drag of 50 kg cm, against current 75 kg cm.

Implementation planned from May - 2013.

3 Brake pedal hold designed tolerances revised & implemented in production since June -2012.

4R 808 friction pads are under validation for performance & wear.

Implementation planned from May 2013, along with mass added caliper.



THANK YOU