統(tǒng)計過程控制-測量系統(tǒng)分析

SPCStatisticProcessControlStatistictechniqueProcessControlSPC由ProductSpec到ProcessParameter由ProductSpec到ProcessParameter1.BasicconceptofSPCVariationControl(Stability)-Statisticalstablestatus-ProcessperformancecanbepredictableCapabilityOver-adjustmentSPC-品管七大手法HistogramCheckSheetParetoCauseandeffectdiagramDefectconcentrationdiagramScatterdiagramControlchartBasicconceptofSPC檢定是否為常態(tài)分配管制圖的中心線X-bar管制圖的管制界限(信賴水平,信賴區(qū)間)ControlLimits=信賴區(qū)間

1.集中趨勢（通常以Xbar作代表）

2.離中趨勢（通常以σ

作代表）

3.信賴水平-被含蓋在特定范圍內的機率

信賴水平-被含蓋在特定范圍內的機率XbarXbar

信賴水平,信賴區(qū)間

信賴水平

信賴區(qū)間

90%

±1.645σ

95%

±1.96σ

99%

±2.575σ

99.73%

±3σ

99.94%±3.5σ99.99%±3.9σ

99.994%±3.99σ信賴水平,信賴區(qū)間,P,Ppk/Cpk信賴水平P信賴區(qū)間Ppk/Cpk90%10%±1.645σ0.54895%5%±1.96σ0.65399%1%±2.575σ

0.85899.73%0.27%

±3σ

199.94%0.06%±3.5σ1.16799.99%100ppm±3.9σ1.399.994%60ppm±3.99σ1.33

ZBasicconceptofSPC用管制圖判別specialcause的準則超過管制界限連續(xù)七點向上連續(xù)七點向下連續(xù)七點向單邊不隨機分布BasicconceptofSPCStatisticalstable=nospecialcause=Undercontrol=processperformancecanbepredictable當制程達到Statisticalstable時才可計算CpkStableProcessUnstableProcessBasicconceptofSPCOver-adjustment:當對commoncause所造成的變異都采取措施調整制程時,等于將一個specialcause加入己穩(wěn)定的制程。使原本穩(wěn)定的制程變成不穩(wěn)定。BasicconceptofSPCPpkCaCpCpkBasicconceptofSPCCa:SensitivetoSpecificationtargetCp:Sensitivetovariation(spread)Cpk:Sensitivetoboth,capabilityindexforstableprocessOnlycommoncausevariationincludedPpk:PerformanceindexBothcommoncauseandspecialcausevariationincludedCp≦CpkBasicconceptofSPCVariation:制程輸出不可避免的差異InherentVariation(固有變異):由commoncause所造成的變異σ=Rbar/d2TotalVariation:由commoncauseandspecialcause所造成的變異PpkCpkCpm

管制圖種類包括計量值管制圖計數(shù)值管制圖Data的種類計量值(location&spread)計數(shù)值計量值管制圖X-BarRChartX-medianRChartX-BarSChartX-RmChart計數(shù)值管制圖種類包括

PPnCU

管制圖的目的預防不良品產出判定制程是否有非機遇因子造成的變異去除非機遇因子造成的變異減小制程的變異改善制程判定制程是否穩(wěn)定制程能力分析100%檢驗還需耍做管制圖嗎?如何做?特殊應用管制圖CUSUMcumulative-SumControlChart)累積和管制圖EWMAexponentiallyWeightedMovingAverageControlChart)指數(shù)加權移勛平均管制圖EVOP(EvolutionaryOperation)-PartAverageTest漸進操作法管制圖AcceptanceControlChart允收管制圖ModifiedControlLimitsControlChart修正界限管制圖ShortRun短制程管制圖

ShortRun短制程管制圖

GuardBandLimit-GRRGuardBandLimit-Cpk

MSAMeasurementSystemAnalysisStatistictechniqueMSControlMSA

MSA

GRRv.s.CPAccuracy&Precision

MSA計量值

Location-Bias,Linearity,StabilitySpread–Repeatability,Reproducibility(GRR)

RangeMethodAverageRangeMethodAverageRangeMethod(WithinPartVariation)ANOVADOE計數(shù)值-ShortMethod-LongMethodBiasStabilityLinearityRepeatabilityReproducibility

GRR-Average-RangeMethod%GRR=%R&R=100(R&R/TV)TV2=R&R2+PV2R&R2

=EV2+AV2

TV2EV2AV2PV2GRR-RangeMethodGRR-Average-RangeMethodANOVAMethodMSAtiming&applicationMSA/APQP/ProductRealizationMSA/FMEA

MSA的目的何種情況可不必做GRR?Cpisgood,notuseforprocessmeasurement,C/Inotrequired?只做GRR,不做Bias,Linearity,Stability可以嗎?MSAformeasurementcan’tberepeatedTheinabilitytotestthesameunitrepeatedlyisamajorobstacletoobtaininganestimateofpuremeasurementerror.DestructivetestingMeasuringatemperature,viscositySamplesobtainedfromtheproductstreamshouldbeasclosedtogetheraspossibleWithfilm,onemightpreferadjacentsamplescollectedinthemachinedirectionratherthanfromdifferentpositionsacrossthewebObtainpairsofsamplesthatareashomogeneousaspossiblewithineachpair,eachpairmaybetestedandthedifferenceinthepairedreadingstakentoobtainanestimateofthevariationofthemeasurementprocessDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionDataCategories&ResolutionPTRatioPrecisionToleranceRatioTheratioofparametertolerancetomeasurementsystemrepeatabilityPT=Tolerance/EV

MSAResultGageresolutiontospectoleranceGageresolutiontoProcessvariationBiasStabilityLinearityR&RWhenshouldMSAbeconductedinAPQP/ProductRealization/ProductLifecycleProductdesignreviewProcessdes