Six Sigma Submission

8/13/2019 Six Sigma Submission

1/19

D M A I CDefine Measure Analyze Improve Control

DDefine

MMeasure

A Analyze

IImprove

CControl

Implementing Six Sigma Quality

at Better Body Manufacturing

Submitted By:

Dipty Joshi u106016

Harbir Singh u106019


2/19

2


Dimension DPM ASM_7Y 172475

ASM_8Y 85824 ASM_3Y 19786

ASM_9Y 3874 ASM_10Y 776

ASM_6Y 4

Overview

ABC Incorporated (ABC) is not achieving Six Sigma quality levels for all criticalBody-Side Sub-Assembly dimensions as requested by their customers.

Ensure that all critical body-side subassembly dimensions are within Six Sigmaquality levels of < 3.4 DPM. C p 2.0 and C pk 1.67.

Change tonnage to > 935 to correct ASM_7Y and ASM_8Y Set clamp position to location 2 for ASM_9Y and ASM_10Y Re-machine A-pillar die to correct A_3Y and ASM_3Y

Determined the correlation between body side and assembly dimensions. Evaluated the significance of Tonnage > 935 for ASM_7Y & ASM_8Y. Conducted a DOE for Clamp position for ASM_9Y & ASM_10Y.

0

50000

100000

150000

200000

A S M

_ 7 Y

A S M

_ 8 Y

A S M

_ 3 Y

A S M

_ 9 Y

A S M

_ 1 0 Y

A S M

_ 6 Y

DP M


3/19

3

D M A I CDefine Measure Analyze Improve ControlProblem Statement & The Goal

ABC Incorporateds customer wants ABC to apply Six Sigma problem solving

methodology to insure that the body side subassembly is achieving Six Sigma quality

levels of less than 3.4 defects per million for all critical body side subassembly

dimensions.

ABC needs an improvement strategy that minimizes the rework costs while achieving the

desired quality objective. ABCs goal is to produce module subassemblies that meet the

customer requirements and not necessarily to insure that every individual stamped

component within the assembly meets it original print specifications sub-system

optimizations vs. local optimization.

+

+

A-Pillar Reinforcement

B-Pillar ReinforcementBody Side Outer

+

+

A-Pillar Reinforcement

B-Pillar ReinforcementBody Side Outer

DDefine


4/19

4

D M A I CDefine Measure Analyze Improve ControlMeasure Phase

Key Variables:

Assembly process variables:

Weld Pattern (density), Clamp Location, and Clamp Weld Pressure

Stamping process variables (body side):

Press Tonnage, Die Cushion Pressure, Material Thickness

Body Assembly Dimensions ASM_1Y through ASM_10Y

MMeasure

4776

172475

85824

19786

3874

0

50000

100000

150000

200000

ASM_7Y ASM_8Y ASM_3Y ASM_9Y ASM_10Y ASM_6Y

DPM

Assembly Dimensions with Highest Defects


5/19

5


Resolution alternatives (based upon past experience):

1. Make adjustments to assembly process settings

2. Reduce variation of components through better control of stamping

process input variables

3. Rework stamping dies to shift component mean deviation that is offtarget and causing assembly defects

Target Performance Level:

All ten critical assembly dimensions at Six Sigma quality level of 3.4 DPM.

C p 2.0 and C pk 1.67

Fish Bone and P-Diagrams:

Understanding potential causes of defects. From this we pick the assembly and

component dimensions that require further analysis

Analyze Phase

A Analyze


6/19

6


For our analysis we will do a DOE to checkfor levels that contribute to better qualityproduct.

Weld Pattern(density)

ClampLocation

Operator

MachineMaterialsMethods

Clamp WeldPressure

PressTonnage

Die CushionPressureMaterial

Thickness

Training

YieldStrength

ElasticLimit

Environment

Temperature

Humidity

Quality ComponentVariability

InspectionProcess Gage R&R Body

Assembly

Analyze Phase

A Analyze

Body Side Sub-AssemblyStamping Process

OutputsBody Side Sub-Assemblies at

Six Sigma quality levels

Control VariablesClamp Location Press TonnageWeld Density Die PressureClamp Pressure

ErrorStates

Dimensionaldefects

Noise VariablesEnvironmentInherent Variation

InputsMaterial Thickness

Yield Strength


7/197


Analysis of ASM_7Y and ASM_8Y

2 7 12

0.0

0.5

1.0

Subgroup Number

A S M

_ 7 Y

Number of runsabout median:Expected number of runs:Longest runabout median:

ApproxP-Value for Clustering: ApproxP-Value for Mixtures:

Number of r uns up or down:Expected number of runs:Longest run up or down:

Approx P-Value for Trends: Approx P-Value for Oscillation:

4.000007.000005.000000.034640.96536

6.000007.666673.000000.107780.89222

Run Chart for ASM_7Y

2 7 12

0.0

0.5

1.0

Subgroup Number

A S M

_ 8 Y

Number of runs aboutmedian:Expected number of runs:Longest run aboutmedian:

ApproxP-Value for Clustering: ApproxP-Value for Mixtures:

Number of runs up or down:Expected number of runs:Longestrun up or down:

Approx P-Value for Trends: Approx P-Value for Oscillation:

4.000007.000005.000000.034640.96536

8.000007.666672.000000.597810.40219

Run Chart for ASM_8Y

Analyze Phase A Analyze

Conclusion: BS_7Y and ASM_7Y are following a similar trend.A correlation chart to study this further shows high correlation.(Pearson correlation, R of 0.701).

0.0 0 .5 1.0

0.0

0.5

1.0

AS M_8 Y

A S M

_ 7 Y

XY Plot of ASM_8 Y and ASM_7Y


8/198

D M A I CDefine Measure Analyze Improve ControlAnalyze Phase A Analyze

-0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8

LSL USL

USLTargetLSLMeanSample NStDev (Within)StDev (Overall)

CpCPUCPLCpk

Cpm

Pp

PPUPPLPpk

PPM< LSL

PPM> USLPPMTotal

PPMUSLPPMTotal

PPMUSLPPMTotal

0.70 *

-0.70 0.11

360.07881220.0791215

2.962.503.432.50

*

2.95

2.493.412.49

0.00

0.000.00

0.00

0.000.00

0.00

0.000.00

Process Data

Potential (Within) Capability

Overall Capability ObservedPerformance Exp."Within" Performance Exp. "Overall" Performance

Within

Overall

Capability of B_7Y

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

LSL USL

USLTargetLSLMeanSample NStDev (Within)

StDev (Overall)

CpCPUCPLCpk

Cpm

PpPPUPPLPpk

PPM< LSLPPM> USLPPMTotal

PPMUSLPPMTotal

PPMUSLPPMTotal

0.700000 *

-0.700000 0.899444

360.149640

0.383691

1.56-0.44 3.56-0.44

*

0.61-0.17 1.39-0.17

0.00666666.67666666.67

0.00908706.09908706.09

15.33698400.06698415.39

Process Data

Potential ( Within) Capability

Overall Capability ObservedPerformance Exp."Within" Performance Exp. "Overall" Performance

Within

Overall698416 DPM0 DPM

0.5 1.0 1.5

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

AS M_7 Y

B S

_ 7 Y

Conclusion: B_7Y has 0 ppm compared to ~700KDPM in BS_7Y.

Furthermore, BS_7Y shows strong correlation ondimension ASM_7Y. (Pearson correlation, R of

0.786).

Capability of BS_7Y


9/199


9 0 5 9 1 5 9 25 93 5 9 4 5

0 .5

1 .0

1 .5

To n n a g e

B S

_ 7 Y

XY Plot of Tonnage vs. BS_7Y

Conclusion: Tonnage values above 935 greatly improves BS_7Y and brings it closerto the mean. Lets see what impact this has on ASM dimensions 7Y, 8Y, 9Y, and10Y by creating a subset of the data looking only at Tonnage > 935.



10/1910


-1. 0 - 0. 5 0 .0 0. 5 1. 0

L S L U S L

C a p a b i l it y A n a l y s i s o f A S M _ 7 Y a t To n n a g e > 9 3 5

US LTa rg e tLS LM e a nS a m p l e NS t D e v ( Wi t h i n )S t D e v ( O v e r a l l)

CpCP UCP LCp k

Cp m

PpPP UPP LPp k

P P M < L S LP P M > U S LP P M To t a l



1 . 0 0 *

- 1 . 0 0 0 . 0 9

1 20 . 1 63 1 7 40 . 1 47 8 5 5

2 . 0 41 . 8 62 . 2 31 . 8 6

*

2 . 2 52 . 0 52 . 4 62 . 0 5

0.000.000.00

0 . 0 00 . 0 10 . 0 1

0 . 0 00 . 0 00 . 0 0

P r o c e s s D a t a

P o t e n t i a l ( Wi t h i n ) C a p a b i l i t y

O ve rall Ca pab il it y O bs erv ed Pe rfo rm an c e E xp . "Wi th in" Perf orm anc e E xp . "O ve rall" Pe rf orm an c e

Wi t h i n

O v e r a ll

-1. 0 - 0. 5 0 .0 0. 5 1. 0

L S L U S L

C a p a b i l i ty A n a l y s i s o f A S M _ 8 Y a t To n n a g e > 9 3 5


CpCP UCP LCp k

Cp m

PpPP UPP LPp k




1 . 0 0 0 0 0 *

- 1 . 00 0 0 0- 0 . 12 8 3 3

1 20 . 1 01 8 2 50 . 0 89 1 6 1

3 . 2 73 . 6 92 . 8 52 . 8 5

*

3 . 7 44 . 2 23 . 2 63 . 2 6

0.000.000.00

0 . 0 00 . 0 00 . 0 0

0 . 0 00 . 0 00 . 0 0


P o t e n t i a l (Wi t hi n ) C a p a b i l i t y

O ve rall C a pab il it y O bs erv ed Pe rfo rm a nc e E xp . "W i th in" Perf orm anc e E xp . "O ve rall" Pe rf orm a nc e

Wi t h i n

O v e r a l l

-1. 0 -0. 5 0 . 0 0 .5 1. 0

L S L US L

C a p a b i l it y A n a l y s i s o f A S M _ 9 Y a t To n n a g e > 9 3 5


CpCP UCP LCp k

Cp m

PpPP UPP LPp k




1 . 0 0 0 0 0 *

- 1 . 00 0 0 0 0 . 5 2 0 8 3

1 20 . 2 06 0 1 00 . 1 77 0 9 8

1 . 6 20 . 7 82 . 4 60 . 7 8

*

1 . 8 80 . 9 02 . 8 60 . 9 0

0.00 0.00 0.00

0 . 0 01 0 0 1 0 . 7 71 0 0 1 0 . 7 7

0 . 0 0 3 4 0 8 . 5 1 3 4 0 8 . 5 1


P o t e n t i a l ( Wi t h i n ) C a p a b i l i t y

O ve rall Ca pab il it y O bs erv ed Pe rfo rm an c e E xp . "Wi th in" Perf orm anc e E xp . "O ve rall" Pe rf orm an c e

Wi t h i n

O v e r a ll

-1. 0 -0 . 5 0. 0 0. 5 1 .0

L S L US L

C a p a b i li ty A n a l y s i s o f A S M _ 1 0 Y a t To n n a g e > 9 3 5


CpCP UCP LCp k

Cp m

PpPP UPP LPp k




1 . 0 0 *

- 1 . 0 0 0 . 3 9

1 20 . 2 15 5 4 10 . 1 87 6 6 3

1 . 5 50 . 9 42 . 1 50 . 9 4

*

1 . 7 81 . 0 82 . 4 71 . 0 8

0.00 0.00 0.00

0 . 0 02 3 2 6 . 7 22 3 2 6 . 7 2

0 . 0 0 5 7 6 . 0 0 5 7 6 . 0 0


P o t e n t i a l (Wi t hi n ) C a p a b i l i t y

O ve rall C a pab il it y O bs erv ed Pe rfo rm a nc e E xp . "W i th in" Perf orm anc e E xp . "O ve rall" Pe rf orm a nc e

Wi t h i n

O v e r a l l

Conclusion: Setting Tonnage to greater than 935 resulted in ASM_7Y and ASM_8Ymeeting the goal of


11/1911


DOE for Response Variable ASM_9Y

DOE factorial analysis shows Clamp Position is the only significant factor in

determining ASM_9Y dimension

DOE Response Optimization for ASM_9Y

Set Clamp Position to Location 2 (level 1) Optimizer recommends setting Weld Density to 1.33 weld per inch (level 1),

but this appears to be a robust parameter, which could be changed for the benefit

of process without reducing quality if processing time or cost shows a benefit.

Optimizer recommends setting Clamp Pressure to 2100 psi (level 1), but this

appears to be a robust parameter, which could be changed for the benefit of process

without reducing quality if processing time or cost shows a benefit.

Run additional tests at recommended settings to confirm results

Weld Density and Clamp Pressure are robust parameters and can be set to optimize

the process capability to maximum level and lowest cost.



12/1912



DOE factorial analysis shows Clamp Position is also the only significant

factor in determining ASM_10Y dimension

DOE Response Optimization for ASM_10Y Setting clamp to location 2 also improves ASM_10Y

Recommend same settings used to improve ASM_9Y to improve process

capability which also allows for no changes to machine setup and helps reduce

possible process concerns

Run additional tests at recommended settings to confirm results Weld Density and Clamp Pressure are robust parameters and can be set to optimize

the process capability to maximum level and lowest cost.


13/1913



DOE factorial analysis shows that no factors are significant

Response Optimization shows no solution for response optimizer

Observe Process Capability of A_3Y and BS_3Y

ASM_3Y and A_3Y have a similar mean shift in the -Y direction

Correlation of Output Variables No dimensional correlations appear to exist between ASM_3Y and

A_3Y or BS_3Y

Stepwise Regression Analysis of BS_3Y Tonnage and Die Pressure appear to be significant in determining

dimension BS_3Y Tonnage values < 920 may improve BS_3Y

Die Pressure appears to have no clear correlation to BS_3Y



14/1914


Process Capability of BS_ 3Y and ASM_3Y at Tonnage < 920

Created subset of body data looking only at dimensions with Tonnage < 935

Tonnage < 920 appears to improve the mean of BS_3Y slightly, but has noimpact on improving the mean of ASM_3Y.

-1.0 -0.5 0.0 0.5 1.0

LSL USL

Capability Analysis of ASM_3Y

USL

TargetLSL

MeanSample N

StDev (Within)

StDev (Overall)

Cp

CPUCPL

Cpk

Cpm

Pp

PPUPPL

Ppk

PPM USLPPM Total

PPM < LSL

PPM > USLPPM Total

PPM < LSL

PPM > USLPPM Total

1

*-1

036

0.0851436

0.0971725

3.91

3.913.91

3.91

*

3.43

3.433.43

3.43

0.00

0.000.00

0.00

0.000.00

0.00

0.000.00

Process Data

Potential (Within) Capability

O ve rall C apab il it y Obs erved P er fo rma nce Exp . "Wi th in" P erf or manc e Exp . "O ve rall" P erf orma nce

Within

Overall

Die remachined to move mean +0.80

Capability of A_3Y and ASM_3Y with +0.80 mmmean offset

Manipulate data for A_3Y and ASM_3Y

by +0.80 mm to simulate re-machining

Process capability shows 0 defects forA_3Y and ASM_3Y with this mean offset



15/1915


Conclusions

From the analysis of ASM_7Y and ASM_8Y we can conclude that:

Setting tonnage > 935 results in ASM_7Y and ASM_8Y meeting the goal

Analyzing ASM_9Y and ASM_10Y helps determine that:

Setting clamp position to location 2, weld density to 1 weld every 1.33

and clamp pressure to 2000 psi helps with dimensions ASM_9Y and

ASM_10Y

Analyzing ASM_3Y helps us conclude that:

Re-machine A-Pillar die to move A_3Y to nominal which could cause

BS_3Y to shift towards nominal effectively shifting ASM_3Y to nominal


16/1916


With the recommended changes the process performance will improve significantlyDimension Mean StDev

OverallDPM_Obsv DPM_Within DPM_Exp P p P pk Cp Cpk

ASM_1Y -0.035 0.165 0 0 0 2.01 1.94 2.47 2.39

ASM_2Y 0.259 0.152 0 0 1 2.20 1.63 2.31 1.71

ASM_3Y 0.000 0.097 0 0 0

ASM_4Y 0.009 0.115 0 0 0 2.90 2.87 3.53 3.50

ASM_5Y -0.330 0.145 0 0 2 2.30 1.54 3.72 2.50

ASM_6Y -0.284 0.160 0 1 4 2.08 1.49 2.24 1.60

ASM_7Y 0.090 0.148 0 0 0 2.25 2.05 2.04 1.86

ASM_8Y -0.128 0.089 0 0 0 3.74 3.26 3.27 2.85

ASM_9Y 0.521 0.180 0 0 0

ASM_10Y 0.395 0.191 0 0 0

A AnalyzeAnalyze Phase


17/1917


Recommendations for improving the process:

Set Tonnage to above 935 to improve ASM_7Y & ASM_8Y

Set Clamp to Location 2 to improve ASM_9Y & ASM_10Y

Re-machine the A-Pillar die to move the mean of A_3Y to nominal which in turnwill move ASM_3Y to nominal

Implement the above recommendations and run additional samples to verify results.

IImproveImprove Phase


18/1918

D M A I CDefine Measure Analyze Improve ControlControl Phase CControl

Recommended controls :

Implement a gauge on the body side component press to monitor tonnage

Implement an alarm and shut-off feature on the body side press if tonnage

falls below 935 tons

Implement poke-yoke clamping fixture that ensures clamp is always in

Position 2

Establish an affordable control plan for ongoing monitoring of the 10

critical assembly dimensions.


19/19

D M A I CDefine Measure Analyze Improve ControlSummary

ABC Incorporated is not achieving Six Sigma quality levels for all critical Body-Side Sub-Assembly dimensions as requested by their customers. BBM needs toapply Six Sigma problem solving methodology to establish an improvement strategythat minimizes rework costs, yet achieves the desired quality objective.

Implement a gauge on the body side component press to monitor tonnage Implement an alarm & shut-off feature on body side press if tonnage falls below 935 Implement poke-yoke clamping fixture that ensures clamp is always in Position 2 Establish control plan for ongoing monitoring of the 10 critical assembly dimensions.

Set Tonnage to above 935 to improve ASM_7Y & ASM_8Y Set Clamp to Location 2 to improve ASM_9Y & ASM_10Y Re-machine the A-Pillar die to move the mean of A_3Y to nominal

Bring the key process output variables within Six Sigma quality level of < 3.4 DPM.C p 2.0 and C pk 1.67

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