六西格玛黑带培训教材

Information,thewayyouwantitProcessCapabilityAnalysis(MeasurePhase)ProcessCapabilityAnalysis2Information,thewayyouwantitScopeofModule•ProcessVariation•ProcessCapability–Specification,ProcessandControlLimits–ProcessPotentialvsProcessPerformance•Short-TermvsLong-TermProcessCapability•ProcessCapabilityforNon-NormalData–Cycle-Time(ExponentialDistribution)–RejectRate(BinomialDistribution)–DefectRate(PoissonDistribution)ProcessCapabilityAnalysis3Information,thewayyouwantitProcessVariationProcessVariationistheinevitabledifferencesamongindividualmeasurementsorunitsproducedbyaprocess.SourcesofVariation•withinunit(positionalvariation)•betweenunits(unit-unitvariation)•betweenlots(lot-lotvariation)•betweenlines(line-linevariation)•acrosstime(time-timevariation)•measurementerror(repeatability&reproducibility)ProcessCapabilityAnalysis4Information,thewayyouwantitTypesofVariationInherentorNaturalVariation•Duetothecumulativeeffectofmanysmallunavoidablecauses•Aprocessoperatingwithonlychancecausesofvariationpresentissaidtobe“instatisticalcontrol”ProcessCapabilityAnalysis5Information,thewayyouwantitTypesofVariationSpecialorAssignableVariation•Maybeduetoa)improperlyadjustedmachineb)operatorerrorc)defectiverawmaterial•Aprocessoperatinginthepresenceofassignablecausesofvariationissaidtobe“out-of-control”ProcessCapabilityAnalysis6Information,thewayyouwantitProcessCapabilityProcessCapabilityistheinherentreproducibilityofaprocess’soutput.Itmeasureshowwelltheprocessiscurrentlybehavingwithrespecttotheoutputspecifications.Itreferstotheuniformityoftheprocess.Capabilityisoftenthoughtofintermsoftheproportionofoutputthatwillbewithinproductspecificationtolerances.Thefrequencyofdefectivesproducedmaybemeasuredina)percentage(%)b)partspermillion(ppm)c)partsperbillion(ppb)ProcessCapabilityAnalysis7Information,thewayyouwantitProcessCapabilityProcessCapabilitystudiescan•indicatetheconsistencyoftheprocessoutput•indicatethedegreetowhichtheoutputmeetsspecifications•beusedforcomparisonwithanotherprocessorcompetitorProcessCapabilityAnalysis8Information,thewayyouwantitProcessCapabilityvsSpecificationLimitsa)b)c)a)Processishighlycapableb)Processismarginallycapablec)ProcessisnotcapableProcessCapabilityAnalysis9Information,thewayyouwantitThreeTypesofLimitsSpecificationLimits(LSLandUSL)•createdbydesignengineeringinresponsetocustomerrequirementstospecifythetoleranceforaproduct’scharacteristicProcessLimits(LPLandUPL)•measuresthevariationofaprocess•thenatural6limitsofthemeasuredcharacteristicControlLimits(LCLandUCL)•measuresthevariationofasamplestatistic(mean,variance,proportion,etc)ProcessCapabilityAnalysis10Information,thewayyouwantitThreeTypesofLimitsDistributionofIndividualValuesDistributionofSampleAveragesProcessCapabilityAnalysis11Information,thewayyouwantitProcessCapabilityIndicesTwomeasuresofprocesscapability•ProcessPotential–Cp•ProcessPerformance–Cpu–Cpl–CpkProcessCapabilityAnalysis12Information,thewayyouwantitProcessPotentialTheCpindexassesseswhetherthenaturaltolerance(6)ofaprocessiswithinthespecificationlimits.6LSLUSLToleranceNaturalTolerancegEngineerinCpProcessCapabilityAnalysis13Information,thewayyouwantitProcessPotentialACpof1.0indicatesthataprocessisjudgedtobe“capable”,i.e.iftheprocessiscenteredwithinitsengineeringtolerance,0.27%ofpartsproducedwillbebeyondspecificationlimits.CpRejectRate1.000.270%1.330.007%1.506.8ppm2.002.0ppbProcessCapabilityAnalysis14Information,thewayyouwantitProcessPotentiala)b)c)a)Processishighlycapable(Cp2)b)Processiscapable(Cp=1to2)c)Processisnotcapable(Cp1)ProcessCapabilityAnalysis15Information,thewayyouwantitProcessPotentialTheCpindexcomparestheallowablespread(USL-LSL)againsttheprocessspread(6).Itfailstotakeintoaccountiftheprocessisnotcenteredbetweenthespecificationlimits.ProcessiscenteredProcessisnotcenteredProcessCapabilityAnalysis16Information,thewayyouwantitProcessPerformanceTheCpkindexrelatesthescaleddistancebetweentheprocessmeanandthenearestspecificationlimit.3USLCpu3LSLCpl3NSLC,CMinimumCplpupkProcessCapabilityAnalysis17Information,thewayyouwantitProcessPerformanceCpkRejectRate1.00.13–0.27%1.10.05–0.10%1.20.02–0.03%1.348.1–96.2ppm1.413.4–26.7ppm1.53.4–6.8ppm1.6794–1589ppb1.7170–340ppb1.833–67ppb1.96–12ppb2.01–2ppbProcessCapabilityAnalysis18Information,thewayyouwantitProcessPerformancea)Processishighlycapable(Cpk1.5)b)Processiscapable(Cpk=1to1.5)c)Processisnotcapable(Cpk1)a)Cp=2Cpk=2b)Cp=2Cpk=1c)Cp=2Cpk1ProcessCapabilityAnalysis19Information,thewayyouwantitExample1SpecificationLimits:4to16gMachineMeanStdDev(a)104(b)102(c)72(d)131DeterminethecorrespondingCpandCpkforeachmachine.ProcessCapabilityAnalysis20Information,thewayyouwantitExample1A5.0464166LSLUSLCp5.043410;431016Min3LSL;3USLMinCpkProcessCapabilityAnalysis21Information,thewayyouwantitExample1B0.1264166LSLUSLCp0.123410;231016Min3LSL;3USLMinCpkProcessCapabilityAnalysis22Information,thewayyouwantitExample1C0.1264166LSLUSLCp5.02347;23716Min3LSL;3USLMinCpk