changqi(john liu) 6sigma

8/4/2019 Changqi(John Liu) 6sigma

1/41

8/25/2011 by CJL TOD Confidential 1

Therm-O-Disc Inc. Product Engineering Dept

Performance ImprovementSix W Project EPR 17340

12D Pressure Release Thermal Sensor

Engineering Analysis

Changqi John Liu, Ph.D

Created on 07/20/2005


2/41


Topics in This Presentation

- Phase (1): Measurement

Project Scope(1)

Problem Statement

Objective

Team Members

Physical Concept for 12D-Temp Control and Pressure Release Valve

Major Output: TFD and Its Standard Deviation Target plan

Cause and Effect Diagram Process Map Analysis

Process Capability Analysis On 3/4/2005 At Project Start

Process Capability Analysis on 04/21/05 and Results Analysis

Improvement (1)-Blank Failure Analysis

Improvement (2)-Second Stress Relief

Improvement (3)-Stability Process

DOE and Results analysis Process Optimization

Confirmation test and results

Conclusions

Project Plan in Future Phase


3/41


Project Scope

Problem Statement: 12D, Style 46338 Copeland Disc is a newlydeveloped Product. The first temp sorting reject rate is

approximately to 450,000 PPM. Annual volume estimated to reach

4.5 million in 2007. The high rate of first reject discs resulted in

reworking labor increase by 6500 hour per year. The high rate of

final scrap disc resulting in cost increased by $ 283,500 per year.

Objective: By optimizing the process parameters to reduce first

rejection scrapped discs by 10% by July 2005. This will yield about

annually $97,600 cost saving per year. ( In long run, we will try to get

scrap discs less than 150,000 PPM. If the final objective is reached it

will generated about annually $189,000 cost reduction.


4/41


Team Members

Changqi Liu: Sr. Project Engineer ( Mansfield ) Chen, Jianbang: Sr. Manufacture Engineer (

China )

Wu, Roy: Quality Engineer ( China )

Zhang, Shear: Process Control Engineer ( China )

Support Management Chua, Ck: Lean Manufacturing Manager

Gurski, Mike: Engineering Manager

Evans, Garry: Quality Control Manager

Mansfield Support

Born, Michael; Mueck, Jeff, Disc Dept


5/41


12D Disc with Different View Point

Snap Action at Open/Close Temp


6/41


Disc Snap Open to Release the Pressure


7/41


Primary Metric

Sigma vs. Date

0

1

2

3

4

5

6

7

3/4/2005 4/3/2005 5/4/2005 6/3/2005 7/4/2005 8/4/2005 9/3/2005 10/4/2005 11/3/2005

Date

Sigma

Projected

Target

Actual

It should be here to get ~ 4.2 o F at the

6 project completion


8/41


Objected Parameter

S No Projected W Average* U S Limit L S Limit Z Level-U Z Level-L PPM-U PPM-L PPM-T FTY

o F o F o F o F %

1 6.50 275.0 268.0 278.0 0.46 1.08 322206 140757 462964 53.70

2 6.00 275.0 268.0 278.0 0.50 1.17 308538 121673 430210 56.98

3 5.50 275.0 268.0 278.0 0.55 1.27 292720 101557 394278 60.57

4 5.00 275.0 268.0 278.0 0.60 1.40 274253 80757 355010 64.50

5 4.50 275.0 268.0 278.0 0.67 1.56 252492 59907 312399 68.76

6 4.00 275.0 268.0 278.0 0.75 1.75 226627 40059 266686 73.33

7 3.50 275.0 268.0 278.0 0.86 2.00 195683 22750 218433 78.16

8 3.00 275.0 268.0 278.0 1.00 2.33 158655 9815 168471 83.15

9 2.50 275.0 268.0 278.0 1.20 2.80 115070 2555 117625 88.24

10 2.00 275.0 268.0 278.0 1.50 3.50 66807 233 67040 93.30

11 1.50 275.0 268.0 278.0 2.00 4.67 22750 2 22752 97.72

12 1.00 275.0 268.0 278.0 3.00 7.00 1350 0 1350 99.87

13 0.50 275.0 268.0 278.0 6.00 14.00 0 0 0 100.00

* Normal Centeris 273o F, It is allowed theactualcentercontrol between272and275o F

W = 4.2 o F ~

1st Sorting Yield to be 70%

The target of the first phase is to obtain first sorting 70 %, final yield to 80%


9/41


Cause Effect Diagram


10/41


Process Flow Chart

DPUHeat Treatment

HT123

BlankingB-3093-1

DPUForming

Auto Bumper

DPUStress Relief

SR 103

DPU1st Thermal Cycle

SR 105

Bimetal RM StripRM 99033 MS-10

DPU2nd Thermal Cycle

SR 105

Receiving Insp.MS-10, RMA-14-6

Blanking Insp.QCW C10457

Cleaning

CL-355 & BF-603

DeburringTM-701 & BF-605

12DDisc Style No 46338

Audit / In-Process

QCW B-1425,12D

701

VA VA

VAVA

VA

VAVA

VA


11/41


Process Flow Chart (2)

DPU

3rd Thermal CycleSR 105

DPU

4th Thermal Cycle

SR 105

Tumbling or SR 103

RFU

Style No 46338

Package

Shipment

4 Pot

Sorting

Yes

No

Cleaning

CL - 355

Dock Audit

BF-609

Inspection Audit

QCW B1425

12D Copeland Disc, Style 46338

VA

NVA

VA VA

VA


12/41


Process Mapping(1)-BlankingType o KPIVs(Xs) SPECs Gages KPOVS ( ys) Spec Data DPCT/WT RTY

%

CR Thickness MS-10, RM14-6 Digital Checker Thickness Unifor +/-I 0.D11

C Grain Size MS-10, RM14-6 Optical Microscope Grain Size No. > 8

C HES Hardness MS-10, RM14-6 Micro-Hardness Tester Hardness Value 210~260

C LES Hardness MS-10, RM14-6 Micro-Hardness Tester Hardness Value 260~315

C Cross Flatness MS-10, RM14-6 Special Tester Cross Curvature < 0.008"

N Bonding Strength MS-10, RM14-6 Special Method, Visual De-layminated 0.005 1 Days CT 99.5

C RM MS-10, RM14-6 Dimple Height B-3093

N Cut MS-10, RM14-6 Visual Control Profile Hx B-3093

N Layer MS-10, RM14-6 Visual Control Profile Hy B-3093

CR Punches Dr. B-3093 Profilimeter Diameter D B-3093

CR Setup BF-701 System Control Number Per Bag 320 o F 0.05 60 Min 95

C Pieces/Bag BF 705 BF 701

Vib. Frequency BF 706 Set

Time BF 707 Timer Round Corner Radii 5E-04 45 Min 99.95

Total 0.054 3 Days 94.6

DPU

Stamping

Raw Material

RM 99033

Cleaning

CL-355, BF603

Heat Treatment

Deburing

Blank AuditCW-10457

VA

VA

VA

NVA

Inspection

MS-10, RM-14-6

Store Room

BF 605

NVA

VA


13/41


Process Mapping(2)-Calibration


14/41


PFMEA(1)

Diff

n

FD/BFD f

each disc res

l

in

s

andard deviati

n wide

Coolin

Rate

Chan

ed

Conveyernot s

ooth to

deliverDiscs are Wrapped

Could not form the discFormin

ability too low

check every 20th lotToo Low Temp, EQ out ofControlchan

e.

Contact

maintenan

ce

2

84Metrology Instron1

Too high Temp, EQ. Out of

Control

Forming ability

ChangedForming conditions

Heat

Treatment

4

Disc equipment tooling wear.

check Burr

Punch tool is dull resulting in too

much burrsharp edge

Tooling

needs

grinding.

1

05Deburr operator1Vibration time too short2

Disc operation effected

by

Edge burr exceeds

.001"Deburring

3

present

Contact

maintenan

ce

3

24

Q.A. Visual

Inspection2

Cleaning process has poor

filtration.4

Disc oil and

contaminationOil or contaminationCleaning

2

dia. and profile.operate correctlyout ofspecification

81

Press operator

checks1Tooling d imensions incorrect8Disc willnotBlank D imensionBlanking1

Recomme

nded

Action(s)

R

P

N

D

e

t

Current Process

ControlsO

c

c

Potential Cause(s)/ Mechanism(s)

ofFailureS

e

v

Potential Effect(s) of

Failure

PotentialFailure

Mode(s)

Process

Function

Requirements

Item

#

JIHGFEDCBA


15/41


Improvement (1)

Effect of RM and Blanking

RM Thickness Uniformity Parameter Uniformity Blank Number of Blank Disc Per Bag

HY Lesson Failure Analysis

Large Number Risk

Low Yield Disc Unstable

It is not the HT and Cleaning Process that depend the Numberof Blank Per Bag.

It is Major the RM Parameter variation to Determine the

Number Per Bag Blank Number Should be Optimized, A Plan was sent to China

plant to do tests Yield vs. Number of Blank per Bag


16/41


Improvement(2)

Second Time Stress Relief

Second Time Stress Relief was done in China

Plant which was originally used to correct the

bad HY blank. After the blank was corrected, it is

still being used in production.

To increase the stability of disc.

It can be get more upper and lower limit

from 268/276 to 268/278 in process. It is proved to increase the life cycles also.


17/41


Process Analysis Step by Step on

4/21/05

PRA AsFed AS-SR As-1stC As-2ndC As-3rdC As-4thC 1stST

o F

Average 297.73 276.49 272.45 273.48 275.49 275.37 276.09

Stdev 7.69 7.24 5.87 7.14 6.14 5.10 4.98

Max 301.10 290.20 285.30 287.40 288.70 286.90 287.10

Min 294.50 264.40 258.70 257.80 265.20 267.30 267.80

Range 6.60 25.80 26.60 29.60 23.50 19.60 22.30


18/41


Process Capability at 4/25/05

284280276272268264

LSL U SL

Process Data

Sample N 120

StDev(With in) 5.25000

StDev(O veral l) 5.12431

LSL 267.00000

Target *

U SL 283.00000

Sample Mean 273.40000

P otential (Within) C apability

C PU 0.61

C pk 0.41

Lower C L 0.33

Upper C L 0.49

C C pk 0.51

C p

O verall C apability

P p 0.52

Lower C L 0.45Upper C L 0.59

P P L 0.42

P P U

0.51

0.62

P pk 0.42

Lower C L 0.34

Upper C L 0.50

C pm *

Lower C L

Lower C L

*

0.44

Upper C L 0.57

C PL 0.41

O bserve d P erformance

PP M < LSL 125000.00

PPM > USL 25000.00

PPM Tota l 150000.00

Exp. Within Performance

PPM < LSL 111413.06

PPM > USL 33731.92

PPM Tota l 145144.98

Exp. O v erall Performance

PPM < LSL 105842.15

PPM > USL 30505.13

PPM Total 136347.28

W ithin

O v erall

Process Capability For 12 D 463 38 Disc Thermal Sensor(using 95.0% confidence)


19/41


Plan in Improvement Phase

Blank Number Optimization: WAs formed vs. numberof blanks per bag (1500, 1750, 2000, 2250pieces/bag)

HT Temp Optimization

Use Appropriated HT System to get the right Open andDifferential ( 275/100 o F) Special for 12D 46338

Punch Effect and Optimization

SR and Stability Optimization

Combination Effect DOE Test To get best two levels for above four factors to do the

design of experimental


20/41


Improvement (3)

Design Experiment Analysis

Affecting Factors HT Temp, Time, Temp Creasing, Cooling Rate, Number per

container

Forming Conditions Penetration 1 and Penetration II

Punch effect: Spherical Radium of 1st Punch

SR Temp, Time, Temp Increasing Rate, Cooling Rate Number Per

Basket

Thermal Cycles

Cycle time, Temp, Number Per Basket

If each factor takes 2 levels, it will be 215 tests. It is too many

tests to be performable. We need a Blocking Method.


21/41


DOE Analysis

In this phase, the DOE will focus on SR andThermal Cycles

Factors selected

Number of Disc Per Container SR - Temp

Thermal Cycle Temp and Cycle Times

Altogether four factors, Each factor has two

levels, The Complete tests are 24. It still toomany. we will take 8 tests


22/41


Table I Factors and Levels Being Selected

Factor Level Low (Code: -1) Level High (Code: +1) Factor Code

Stress Relief Temp 550 o F / 20 Min. 700 o F / 20 Min. A

Disc # per Basket 250 Per Container 500 Per Container B

Cycle Number 2 Cycles 4 Cycles C

Cycle Temp 310 o F/10 Min 550 o F /10 Min D

StdOrder RunOrder SR T Disc No Cycle No TC Tem

4 1 1 1 -1 -1

1 2 -1 -1 -1 -1

5 3 -1 -1 1 1

6 4 1 -1 1 -13 5 -1 1 -1 1

7 6 -1 1 1 -1

2 7 1 -1 -1 1

8 8 1 1 1 1


23/41


Planned Tests

Run No SR Temp Disc No PerB Cycle No. C- Temp

1 550F/20 Min 250 2 310F/10 Min

2 550F/20 Min 500 4 310F/10 Min

3 550F/20 Min 250 4 550F/10 Min

4 700F/20 Min 500 4 550F/10 Min

5 700F/20 Min 250 2 550F/10 Min

6 550F/20 Min 500 2 550F/10 Min

7 700F/20 Min 250 4 310F/10 Min

8 700F/20 Min 500 2 310F/10 Min


24/41


Test Results

Run I Run II Run III Run IV

TFD BFD TFD BFD TFD BFD TFD BFD

Average 297.1 185.2 293.0 184.0 294.1 181.4 294.0 187.6

Stdev 6.62 5.20 6.59 4.95 6.87 5.13 7.24 4.41

Max 306.7 195.3 309.3 195.3 309.7 195.1 313.3 195.6

Min 282.4 175.2 280.5 169.3 283.7 174.3 284.6 180.6

Range 24.3 20.1 28.8 26.0 26.0 20.8 28.7 15.0

RUN V RUN VI Run VII Run VIII


Average 275.6 174.9 276.9 176.5 276.8 175.5 274.9 175.7

Stdev 4.88 4.15 4.85 5.40 6.85 4.35 6.43 6.04

Max 285.9 188.0 286.5 195.8 292.8 184.2 286.7 195.3

Min 265.2 168.2 268.3 167.7 264.4 168.8 263.1 164.5

Range 20.7 19.8 18.2 28.1 28.4 15.4 23.6 30.8

30 pieces of samples were taken to do stat check


25/41


TFD Stdev

Run No SR Disc No TC No TC Temp Stdev

o F Pieces Cycles o F o F

1 550 250 2 310 5.28

2 550 250 4 550 5.483 550 500 2 550 5.12

4 550 500 4 310 5.99

5 700 250 2 550 3.58

6 700 250 4 310 4.09

7 700 500 2 310 4.81

8 700 500 4 550 5.58


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Main Effect on The Results

MeanofResults

1-1

5.50

5.25

5.00

4.75

4.50

1-1

1-1

5.50

5.25

5.00

4.75

4.50

1-1

SR T Disc No

Cycle No T C T em

Main Effects Plot (data means) for Results

High Temp will resulting in a lower Standard Deviation

Less number of discs in a container will result in a lower Stdev

Less thermal cycles will result in a lower Stdev

Thermal Cycles Temp will not be of large effect


27/41


Interaction

SR T

1-1 1-1 1-1

6

5

4

Disc No

6

5

4

Cycle No

6

5

4

TC Tem

SR T

-1

1

Di

-1

1

Cycl

-1

1

InteractionPlot (datameans) for Results

When SR temp at high level, 250 disc discs in a container willresult in a lower standard deviation

When 2 cyclic number was taken with the high ST temp, it will

help to reduce the stdev


28/41


Analysis of Variance for Results (coded units)

Source DF Seq SS Adj SS Adj MS F P

Main Effects 4 3.7040 3.7040 0.9260 * *

2-Way Interactions 3 0.8157 0.8157 0.2719 * *

Residual Error 0 * * *

Total 7 4.5197


29/41


Estimated Effects and Coefficients for Results

(coded units)

Term Effect Coef

Constant 4.9913

SR T -0.9525 -0.4763

Disc No 0.7675 0.3837

Cycle No 0.5875 0.2938

TC Tem -0.1025 -0.0513

SR T*Disc No 0.5925 0.2963


30/41


Effect of Factors

Term

Effect

AC

D

AD

C

AB

B

A

3.53.02.52.01.51.00.50.0

3.306Factor

TC Tem

Name

A S R T

B Disc N o

C C y cle N o

D

Pare to Chart of the Effects(response is Results, Alpha = .05)

Lenth's PSE = 0.87825

Thermal Cycle Temp (D) effect is small

AC and AD effect are small either


31/41


Factorial Fit: Results versus SR T, Disc No,

Cycle No

After taking away the thermal temp factor:Estimated Effects and Coefficients for Results (coded units)

Term Effect Coef SE Coef T P

Constant 4.9913 0.07490 66.64 0.000SR T -0.9525 -0.4763 0.07490 -6.36 0.008

Disc No 0.7675 0.3837 0.07490 5.12 0.014

Cycle No 0.5875 0.2938 0.07490 3.92 0.029

SR T*Disc No 0.5925 0.2962 0.07490 3.96 0.029

S = 0.211847 R-Sq = 97.02% R-Sq(adj) = 93.05%


32/41


Main Effect Factors

Term

Standardized Effect

C

AB

B

A

76543210

3.182 Factor NameA SR T

B Disc No

C C ycle No

Pareto Chart of the Standardized Effects(response is Results, Alpha = .05)

The main factors of the A SR Temp, B - Disc Number per container,

C Number of thermal cycles


33/41


Residuals

Residual

Percent

0.40.20.0-0.2-0.4

99

90

50

10

1

Fitted Value

Residual

5.55.04.54.03.5

0.2

0.1

0.0

-0.1

-0.2

Residual

F

requency

0.20.10.0-0.1-0.2

1.00

0.75

0.50

0.25

0.00

Observation Order

Residual

87654321

0.2

0.1

0.0

-0.1

-0.2

Normal Probability Plot of the Residuals Residuals Versus the Fitted Values

Hist og ram o f t he R esid uals R esid uals Versus t he Ord er o f t he Dat a

Residual Plots for Results


34/41


Analysis of Variance for Results (coded units)

Source DF Seq SS Adj SS Adj MS F P

Main Effects 3 3.6829 3.6829 1.22765 27.35 0.011

2-Way Interactions 1 0.7021 0.7021 0.70211 15.64 0.029

Residual Error 3 0.1346 0.1346 0.04488

Total 7 4.5197


35/41


Effect Equation Obtained

= 4.9913 0.476TSR+ 0.384NDisc + 0.2938NCycles +0.296TSRNDisc

Optimized Process Conditions

SR Temp (TSR) 700o F/ 20Min

Number of Disc (NDisc) 250 Pieces Per Container Thermal Cycles (NCycles) 2 Cycles

Thermal Cycle Temp 550 o F /20 Min


36/41


Confirmation Test & More Improvement

Group I SR 700 F/20 Min, 250 pieces/PC ;2 Cycles/Air Cooling, 550 F/10 Min

Group II SR 700 F/20 Min, 250 pieces/PC 2 SR ;

2 Cycles/Air Cooling, 550 F/10 Min

To See if 2 times of SR will improve the Sigma

Group III SR 700 F/20Min, 250 Pieces/PC;

4 Cycles, 310F/10 Min

Sorting Oil heating and Cooling

Group IV SR 700 F/20Min, 250 Pieces/PC-2 SR ;4 Cycles , 310F/10 Min

Sorting Oil Heating and Cooling,


37/41


Confirmation Test Results

Test 1 Test 2 Test 3 Test 4


Averag

e 274.30 174.17 271.45 174.07 270.94 173.08 271.27 174.85

Stdev 4.03 3.81 3.59 2.89 2.43 2.78 3.92 4.03

Max 280.30 178.50 282.60 180.10 277.60 177.30 282.70 189.90

Min 263.30 164.40 264.60 169.60 265.90 166.10 263.70 166.80

Range 17.00 14.10 18.00 10.50 11.70 11.20 19.00 23.10


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Primary Metric

Sigma vs. Date

0

1

2

3

4

5

6

7

3/4/2005 4/3/2005 5/4/2005 6/3/2005 7/4/2005 8/4/2005 9/3/2005 10/4/2005 11/3/2005

Date

Sigma

Projected

Target

Actual

We are here W ~ 5 o F

Objective ~ 4.2 o F on 7/20/05

We have now reached: < 4 o F


39/41


Projected Parameters

S No Projected W Average* U S Limit L S Limit Z Level-U Z Level-L PPM-U PPM-L PPM-T Yield

o F o F o F o F %

1 6.50 275.0 268.0 278.0 0.46 1.08 322206 140757 462964 53.70

2 6.00 275.0 268.0 278.0 0.50 1.17 308538 121673 430210 56.98

3 5.50 275.0 268.0 278.0 0.55 1.27 292720 101557 394278 60.57

4 5.00 275.0 268.0 278.0 0.60 1.40 274253 80757 355010 64.50

5 4.50 275.0 268.0 278.0 0.67 1.56 252492 59907 312399 68.76

6 4.00 275.0 268.0 278.0 0.75 1.75 226627 40059 266686 73.33

7 3.50 275.0 268.0 278.0 0.86 2.00 195683 22750 218433 78.16

8 3.00 275.0 268.0 278.0 1.00 2.33 158655 9815 168471 83.15

9 2.50 275.0 268.0 278.0 1.20 2.80 115070 2555 117625 88.24

10 2.00 275.0 268.0 278.0 1.50 3.50 66807 233 67040 93.30

11 1.50 275.0 268.0 278.0 2.00 4.67 22750 2 22752 97.72

12 1.00 275.0 268.0 278.0 3.00 7.00 1350 0 1350 99.87

13 0.50 275.0 268.0 278.0 6.00 14.00 0 0 0 100.00

* Normal Centeris 273F, It is allowed theactualcentercontrol between272and275o F

When < 4 o F,

1st sorting Yield will be ~ 75%


40/41


Conclusions

By Optimizing the Stability Conditions as below: SR 700 o F / 20 Min. 250 pieces/Per Condition

2 Thermal Cycle with temp as 550 o F /10 Min.

It is able to improve the performance:

The first Sorting yield increased from 50 % to 75% The final yield will be more than 80%.

This corresponds to an approx labor saving of 4000hrs.

The 10% yield improvement corresponds to a costreduction of approx. $80,000 per year. ( 4 milliondiscs per year in production )


41/41


Future Works

Effect of the blank number on the Forming Effect of Punch Spherical Radius on the

Forming

Second Phase ImprovementTarget: 10-15% improvement

TFD Stdev Target should be < 1.75 o F

Third Phase Improvement Long Run

Maximum is about 19.9 % of improvement

TFD Stdev Target should be < 1 o F

changqi(john liu) 6sigma

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