MSA测量系统分析报告(ppt 63页)（英文版）.ppt

1、TrainingMaterialforMEASUREMENTSYSTEMANALYSIS,Contents:,INTRODUCTIONFORMEASUREMENTSYSTEMANALYSISGENERALMETHODSILLUSTRATIONFORMEASUREMENTSYSTEMANALYSISVARIABLEGAGEANALYSISMETHOD1)THEAVERAGE-RANGEMETHOD2)THEANOVAMETHODATTRIBUTEGAGEANALYSISMETHOD1)SHORTMETHOD2)HYPOTHESISTESTANALYSIS3)SIGNALDETECTIONTHEO

2、RY4)LONGMETHODACCEPTABILITYCRITERIACONCLUSIONFOURMETHODSCOMPARISON,Introduction:BasicrequirementsbyQS-9000Stability;LinearityBiasisthedifferencebetweentheobservedaverageofmeasurementsandareferencevalue.Biasisoftenreferredtoasaccuracy.Itisasystematicerrorcomponentofthemeasurementsystem,Introduction:W

3、heredoesthevariationofmeasurementsystemcomefrom?,TheFiveCharacterizationsofMeasurementSystem:1.LocationVariation:Bias;Stability;LinearityStability(Alias:Drift):Stabilityisthetotalvariationinthemeasurementsobtainedwithameasurementsystemonthesamemasterorpartswhenmeasuringasinglecharacteristicoveranext

4、endedtimeperiod.Astablemeasurementprocessisinstatisticalcontrolwithrespecttolocation.,Stability,Introduction:Wheredoesthevariationofmeasurementsystemcomefrom?,TheFiveCharacterizationsofMeasurementSystem:1.LocationVariation:Bias;Stability;LinearityLinearityisthedifferenceinthebiasvaluesthroughtheexpe

5、ctedoperatingrangeofthemeasurementinstrument.Itisasystematicerrorcomponentofthemeasurementsystem.,Linearity,Introduction:Wheredoesthevariationofmeasurementsystemcomefrom?,TheFiveCharacterizationsofMeasurementSystem:2.WidthVariation:Repeatability;Reproducibility;GageRReproducibility;GageRReproducibil

6、ity;GageRvalueslessthan0.4indicatepooragreement.Repeatabovestep,wecangotfollowingkappameasuresfortheappraisers:Table4,AnalysisTechniques:AttributeGageStudy,a-ef,N-ef,142-79.2,150-79.2,Table4,Usingthesamestepstocalculatedthekappameasuretodeterminetheagreementofeachappraisertothereferencedecision:Tabl

7、e5TotalsummaryonTable6:,AnalysisTechniques:AttributeGageStudy,Table5,AnalysisTechniques:AttributeGageStudy,AnalysisTechniques:AttributeGageStudy,TheAIAGMSAreferencemanualedition3providesacceptabilitycriteriaforeachappraisersresults:Definition:FalseAlarmThenumberoftimesofwhichtheoperator(s)identifyag

8、oodsampleasabadone.MissThenumberoftimesofwhichtheoperatorsidentifyabadsampleasagoodone.,AnalysisTechniques:AttributeGageStudy,Sosummarizingalltheinformationoftheexamplewiththistable:Table7,AnalysisTechniques:AttributeGageStudy,Conclusion:ThemeasurementsystemwasacceptablewithappraiserB,marginalwithap

9、praiserA,andunacceptableforC.SoweshalldetermineifthereisamisunderstandingwithappraiserCthatrequiresfurthertrainingandthenneedtore-doMSA.Thefinaldecisioncriteriashouldbebasedontheimpacttotheremainingprocessandfinalcustomer.Generally,themeasurementsystemisacceptableifall3factorsareacceptableormarginal

10、.Minitabalsocanperformattributegageanalysis,butitdidntdeclaretheacceptabilitycriteria,soitisnotrecognizedbyQS9000standard.,AnalysisTechniques:AttributeGageStudy,SignalDetectionTheoryistodetermineanapproximationofthewidthoftheregionIIareasoastocalculatethemeasurementsystemGRForthelargest(orsmallest)p

11、art,thevaluemustbea=20;Forthe6otherparts,thevalue1a19.,AnalysisTechniques:AttributeGageStudy,1Appraiser,20Trials,AnalysisTechniques:AttributeGageStudy,Example:Weuseafillergagetomeasurethefittinggapbetweenbatteryandhandphonewhichspecificationis00.2mm.Thenumberofacceptsforeachpartare:Table10,Table10,A

12、nalysisTechniques:AttributeGageStudy,Thesecondstepistheacceptanceprobabilitiescalculationforeachpartusingthebinomialadjustments:,Table11,AnalysisTechniques:AttributeGageStudy,Thethirdstep:PlotGagePerformanceCurvewithpartreferencevalueXTasXaxis,andtheprobabilityofacceptancePaasYaxis,GagePerformanceCu

13、rve,AnalysisTechniques:AttributeGageStudy,Thefourthstep:BaseonGagePerformanceCurvetofindXTvalueatPa=0.5%andPa=99.5%(usingnormalprobabilitypapercangetmoreaccurateestimates).WealsocanuseStatisticalForecastcalculationtogettheXTvalue.XT=0.264atPa=0.5%XT=0.184atPa=99.5%Bias=XT(atPa=0.5%)-USL=0.2640.2=0.0

14、64TherepeatabilityisdeterminedbyfindingthedifferencesoftheXTvaluecorrespondingtoPa=99.5%andPa=0.05%anddividingbyanadjustmentfactorof1.08.,AnalysisTechniques:AttributeGageStudy,Conclusion:Becausethefillergagerepeatabilityis7.4%,Biasis6.4%.Bothofthemarelessthan10%,sothegagecanbeacceptedtouse.,FourMeth

15、odsComparison,Thefourmethodsforattributemeasurementstudyhaverespectivefeature.TheShortmethodlooklikesimple,butitneedtoselectenoughpartswhichareslightlybelowandabovebothspecificationlimits,andmustmeasurevariablereferencevalueinadvance.HypothesisTestdidntneedtomeasurethevariablereferencevalue,soitisfeasibleformanufacturing,butitneedlargesamplesize.SignalDetectionmethodcandetermineanapproximationofthewidthoftheregionIIareasoastocalculatethemeasurementsystemGR&R.LongmethodisusedtheconceptoftheGagePerformanceCurve(GPC)toassesstherepeatabilityandbiasofthemeasurementsystem.Whentheim