Six Sigma: Advanced Tools for Black Belts and Master Black Belts

406 Pages·2006·10.83 MB·English

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Six Sigma
SixSigma:AdvancedToolsforBlackBeltsandMasterBlackBelts Edited by L.C.Tang,T.N.Goh,H.S.Yamand
T. Yoap © 2006JohnWiley&Sons,Ltd. ISBN: 0-470-02583-2
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Six Sigma
Advanced Tools for Black Belts and
Master Black Belts
Loon Ching Tang
NationalUniversityofSingapore,Singapore
Thong Ngee Goh
NationalUniversityofSingapore,Singapore
Hong See Yam
SeagateTechnologyInternational,Singapore
Timothy Yoap
FlextronicsInternational,Singapore
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LibraryofCongressCataloging-in-PublicationData
Sixsigma:advancedtoolsforblackbeltsandmasterblackbelts/LoonChingTang...[etal.].
p. cm.
Includesbibliographicalreferencesandindex.
ISBN-13:978-0-470-02583-3(cloth:alk.paper)
ISBN-10:0-470-02583-2(cloth:alk.paper)
1.Sixsigma(Qualitycontrolstandard) 2.Totalqualitymanagement. I.Tang,LoonChing.
TS156.S5372006
658.5(cid:3)62--dc22
2006023985
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ISBN-10 0-470-02583-2(HB)
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Contents
Preface.................................................................................................. xi
PARTA: SIXSIGMA:PAST,PRESENTANDFUTURE
1 SixSigma:APreamble..................................................................... 3
H.S.Yam
1.1 Introduction.............................................................................. 3
1.2 SixSigmaRoadmap:DMAIC....................................................... 4
1.3 SixSigmaOrganization.............................................................. 7
1.4 SixSigmaTraining..................................................................... 8
1.5 SixSigmaProjects...................................................................... 10
1.6 Conclusion............................................................................... 17
References....................................................................................... 17
2 AStrategicAssessmentofSixSigma.................................................. 19
T.N.Goh
2.1 Introduction.............................................................................. 19
2.2 SixSigmaFramework................................................................. 20
2.3 SixSigmaFeatures..................................................................... 21
2.4 SixSigma:ContrastsandPotential............................................... 22
2.5 SixSigma:InherentLimitations.................................................... 23
2.6 SixSigmaintheKnowledgeEconomy.......................................... 25
2.7 SixSigma:ImprovingtheParadigm.............................................. 27
References....................................................................................... 28
3 SixSigmaSWOT............................................................................. 31
T.N.GohandL.C.Tang
3.1 Introduction.............................................................................. 31
3.2 OutlineofSixSigma................................................................... 32
3.3 SWOTAnalysisofSixSigma....................................................... 32
3.4 FurtherThoughts....................................................................... 37
References....................................................................................... 39
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vi Contents
4 TheEssenceofDesignforSixSigma.................................................. 41
L.C.Tang
4.1 Introduction.............................................................................. 41
4.2 TheIDOVRoadmap................................................................... 42
4.3 TheFuture................................................................................ 48
References....................................................................................... 48
5 FortifyingSixSigmawithOR/MSTools............................................. 49
L.C.Tang,T.N.GohandS.W.Lam
5.1 Introduction.............................................................................. 49
5.2 IntegrationofOR/MSintoSixSigmaDeployment.......................... 50
5.3 ANewRoadmapforSixSigmaBlackBeltTraining......................... 52
5.4 CaseStudy:ManpowerResourcePlanning.................................... 58
5.5 Conclusions.............................................................................. 68
References....................................................................................... 68
PARTB: MEASUREPHASE
6 ProcessVariationsandTheirEstimates............................................... 73
L.C.TangandH.S.Yam
6.1 Introduction.............................................................................. 73
6.2 ProcessVariability..................................................................... 76
6.3 NestedDesign........................................................................... 79
References....................................................................................... 83
7 FishboneDiagramsvs.MindMaps.................................................... 85
TimothyYoap
7.1 Introduction.............................................................................. 85
7.2 TheMindMapStepbyStep........................................................ 86
7.3 ComparisonbetweenFishboneDiagramsandMindMaps............... 87
7.4 ConclusionandRecommendations............................................... 91
References....................................................................................... 91
8 CurrentandFutureRealityTrees....................................................... 93
TimothyYoap
8.1 Introduction.............................................................................. 93
8.2 CurrentRealityTree................................................................... 94
8.3 FutureRealityTree(FRT)............................................................ 97
8.4 ComparisonwithCurrentSixSigmaTools..................................... 101
8.5 ConclusionandRecommendations............................................... 105
References....................................................................................... 105
9 ComputingProcessCapabilityIndicesforNonnormalData:AReview
andComparativeStudy.................................................................... 107
L.C.Tang,S.E.ThanandB.W.Ang
9.1 Introduction.............................................................................. 107
9.2 SurrogatePCIsforNonnormalData............................................. 108
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Contents vii
9.3 SimulationStudy....................................................................... 113
9.4 DiscussionofSimulationResults.................................................. 127
9.5 Conclusion............................................................................... 128
References....................................................................................... 129
10 ProcessCapabilityAnalysisforNon-NormalDatawithMINITAB........ 131
TimothyYoap
10.1 Introduction............................................................................ 131
10.2 IllustrationoftheTwoMethodologiesUsingaCaseStudyDataSet... 132
10.3 AFurtherCaseStudy............................................................... 141
10.4 MonteCarloSimulation............................................................ 145
10.5 Summary................................................................................ 149
References....................................................................................... 149
PARTC: ANALYZEPHASE
11 Goodness-of-FitTestsforNormality................................................... 153
L.C.TangandS.W.Lam
11.1 Introduction............................................................................ 153
11.2 UnderlyingPrinciplesofGoodness-of-FitTests............................. 154
11.3 PearsonChi-SquareTest............................................................ 155
11.4 EmpiricalDistributionFunctionBasedApproaches....................... 157
11.5 Regression-BasedApproaches.................................................... 163
11.6 Fisher’sCumulantTests............................................................ 167
11.7 Conclusion.............................................................................. 170
References....................................................................................... 170
12 IntroductiontotheAnalysisofCategoricalData.................................. 171
L.C.TangandS.W.Lam
12.1 Introduction............................................................................ 171
12.2 ContingencyTableApproach..................................................... 173
12.3 CaseStudy.............................................................................. 176
12.4 LogisticRegressionApproach.................................................... 181
12.5 Conclusion.............................................................................. 193
References....................................................................................... 193
13 AGraphicalApproachtoObtainingConfidenceLimitsofC .............. 195
pk
L.C.Tang,S.E.ThanandB.W.Ang
13.1 Introduction............................................................................ 196
13.2 GraphingC ,kandp................................................................. 197
p
13.3 ConfidenceLimitsfork............................................................. 199
13.4 ConfidenceLimitsForC ......................................................... 201
pk
13.5 ASimulationStudy.................................................................. 203
13.6 IllustrativeExamples................................................................ 206
13.7 ComparisonwithBootstrapConfidenceLimits............................. 207
13.8 Conclusions............................................................................ 209
References....................................................................................... 210
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14 DataTransformationforGeometricallyDistributed
QualityCharacteristics..................................................................... 211
T.N.Goh,M.XieandX.Y.Tang
14.1 Introduction............................................................................ 211
14.2 ProblemsofThree-SigmaLimitsfortheGChart........................... 212
14.3 SomePossibleTransformations.................................................. 213
14.4 SomeNumericalComparisons................................................... 216
14.5 SensitivityAnalysisofthe QTransformation................................ 219
14.6 Discussion.............................................................................. 221
References....................................................................................... 221
15 DevelopmentofAMoistureSoakModelForSurface
MountedDevices............................................................................. 223
L.C.TangandS.H.Ong
15.1 Introduction............................................................................ 223
15.2 ExperimentalProcedureandResults........................................... 225
15.3 MoistureSoakModel................................................................ 227
15.4 Discussion.............................................................................. 234
References....................................................................................... 236
PARTD: IMPROVEPHASE
16 AGlossaryforDesignofExperimentswithExamples.......................... 239
H.S.Yam
16.1 FactorialDesigns...................................................................... 239
16.2 AnalysisofFactorialDesigns..................................................... 242
16.3 ResidualAnalysis..................................................................... 243
16.4 TypesofFactorialExperiments................................................... 244
16.5 FractionalFactorialDesigns....................................................... 246
16.6 RobustDesign......................................................................... 250
17 SomeStrategiesforExperimentationunderOperationalConstraints..... 257
T.N.Goh
17.1 Introduction............................................................................ 257
17.2 HandlingInsufficientData........................................................ 258
17.3 InfeasibleConditions................................................................ 258
17.4 VariantsofTaguchiOrthogonalArrays........................................ 260
17.5 IncompleteExperimentalData................................................... 262
17.6 AccuracyofLeanDesignAnalysis.............................................. 262
17.7 ANumericalIllustration........................................................... 263
17.8 ConcludingRemarks................................................................ 264
References....................................................................................... 265
18 TaguchiMethods:SomeTechnical,Culturaland
PedagogicalPerspectives.................................................................. 267
T.N.Goh
18.1 Introduction............................................................................ 268
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Contents ix
18.2 GeneralApproachestoQuality.................................................. 268
18.3 StagesinStatisticalApplications................................................. 269
18.4 TheTaguchiApproach.............................................................. 272
18.5 Taguchi’s‘StatisticalEngineering’............................................... 273
18.6 CulturalInsights...................................................................... 282
18.7 TrainingandLearning.............................................................. 286
18.8 ConcludingRemarks................................................................ 291
18.9 Epilogue................................................................................. 292
References....................................................................................... 293
19 EconomicalExperimentationvia‘LeanDesign’................................... 297
T.N.Goh
19.1 Introduction............................................................................ 297
19.2 TwoEstablishedApproaches..................................................... 298
19.3 RationaleofLeanDesign........................................................... 298
19.4 PotentialofLeanDesign........................................................... 299
19.5 IllustrativeExample................................................................. 302
19.6 PossibleApplications................................................................ 303
19.7 ConcludingRemarks................................................................ 305
References....................................................................................... 306
20 AUnifiedApproachforDualResponseSurfaceOptimization.............. 307
L.C.TangandK.Xu
20.1 Introduction............................................................................ 307
20.2 ReviewofExistingTechniquesforDualResponse
SurfaceOptimization................................................................ 308
20.3 Example1............................................................................... 314
20.4 Example2............................................................................... 319
20.5 Conclusions............................................................................ 320
References....................................................................................... 322
PARTE: CONTROLPHASE
21 EstablishingCumulativeConformanceCountCharts........................... 325
L.C.TangandW.T.Cheong
21.1 Introduction............................................................................ 325
21.2 BasicPropertiesoftheCCCChart............................................... 326
21.3 CCCSchemewithEstimatedParameter....................................... 327
21.4 ConstructingACCCChart........................................................ 330
21.5 NumericalExamples................................................................ 336
21.6 Conclusion.............................................................................. 339
References....................................................................................... 340
22 SimultaneousMonitoringoftheMean,VarianceandAutocorrelation
StructureofSeriallyCorrelatedProcesses........................................... 343
O.O.AtienzaandL.C.Tang
22.1 Introduction............................................................................ 344
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22.2 TheProposedApproach............................................................ 345
22.3 ARLPerformance..................................................................... 346
22.4 NumericalExample.................................................................. 349
22.5 Conclusion.............................................................................. 351
References....................................................................................... 352
23 StatisticalProcessControlforAutocorrelatedProcesses:ASurveyand
AnInnovativeApproach................................................................... 353
L.C.TangandO.O.Atienza
23.1 Introduction............................................................................ 353
23.2 DetectingOutliersandLevelShifts............................................. 355
23.3 BehaviorofλLS,t....................................................................... 358
23.4 ProposedMonitoringProcedure................................................. 363
23.5 Conclusions............................................................................ 366
References....................................................................................... 368
24 CumulativeSumChartswithFastInitialResponse.............................. 371
L.C.TangandO.O.Atienza
24.1 Introduction............................................................................ 371
24.2 FastInitialResponse................................................................. 374
24.3 Conclusions............................................................................ 379
References....................................................................................... 379
25 CUSUMandBackwardCUSUMforAutocorrelatedObservations......... 381
L.C.TangandO.O.Atienza
25.1 Introduction............................................................................ 381
25.2 BackwardCUSUM................................................................... 382
25.3 SymmetricCumulativeSumSchemes.......................................... 387
25.4 CUSUMSchemeforAutocorrelatedObservations......................... 391
25.5 Conclusion.............................................................................. 404
References....................................................................................... 405
Index.................................................................................................... 407
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Preface
TheonlyplacewhereQualitycomesbeforeStatisticsisinthedictionary.
(T.N.Goh)
SixSigmahascomealongwaysinceitsintroductioninthemid-1980s.Ourassociation
withthesubjectbeganinthe1990swhenanumberofmultinationalcorporationsin
SingaporebegantodeploySixSigmainpursuitofbusinessexcellence.Priortothis,
someofushadbeenworkingonstatisticalqualityimprovementtechniquesformore
thantwodecades.ItwasapparentattheoutsetthatthestrengthofSixSigmaisnotin
introducingnewstatisticaltechniquesasitreliesonwell-establishedandproventools;
SixSigmaderivesitspowerfromthewaycorporatemindsetsarechangedtowards
theapplicationofstatisticaltools,fromtopbusinessleaderstothoseontheproduction
floor.Weareprivilegedtobepartofthisforceforchangethroughourinvolvement
inSixSigmaprogramswithmanycompaniesintheAsia-Pacificregion.
Overthelastdecade,asSixSigmahastakenrootinanumberofcorporationsinthe
region,thelimitationsofexistingtoolshavesurfacedandthedemandforinnovative
solutionshasincreased.ThishascoincidedwiththerapidevolutionofSixSigmaas
itpermeatedacrossvariousindustries,andinmanycasestheconventionalSixSigma
toolsetisnolongersufficienttoprovideadequatesolutions.Thishasopenedupmany
researchopportunitiesandmotivatedclosecollaborationsbetweenacademiaandin-
dustrialpractitioners.Thisbookrepresentspartofthisefforttobringtogetherpracti-
tionersandacademicstoworktowardsthecommongoalofprovidinganadvanced
referenceforSixSigmaprofessionals,particularlyBlackBeltsandMasterBlackBelts.
Thebookisorganizedintofiveparts,offivechapterseach.Eachofthepartsrep-
resentsrespectivelythedefine,measure,analyze,improveandcontrolphasesofthe
traditional Six Sigma roadmap. Part A presents a strategic assessment of Six Sigma
anditsSWOTanalysis,followedbydiscussionsofcurrentinterestsinSixSigma,in-
cludingDesignforSixSigmaaswellasanewimprovementroadmapfortransactional
SixSigma.
In Part B, basic concepts of variability and some useful qualitative tools such as
mindmapsandrealitytreesarepresented.Capabilityanalysisfornon-normaldatais
alsodiscussedintwochaptersfocusingrespectivelyonthetheoreticalandpractical
aspects.
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