MSA测量系统分析(英文版)培训讲学课件

SPCforTestSystem§GaugeR&RSPCforTestSystem§GaugeR&R有多少個黑點？有多少個黑點？這些橫線是不是平行的？這些橫線是不是平行的？是靜的還是動的？是靜的還是動的？三個正方形三個正方形幾何謎題幾何謎題沒有適當的量測工具就無法管理品質!!沒有適當的量測工具比較式絕對式待測量轉換訊息標準值顯示量測儀量測之種類待測量標準量轉換訊息轉換訊息比測儀顯示轉換放大比較式待測量轉換訊息標準值顯示量測儀量測之種類待測量標準量轉BasicConceptsEveryProcessproducea“Product”.EveryproductpossessesQualities(Features)EveryQualityFeatureCanbemeasuredTotalVariation=ProductVariation+MeasurementVariationSomeVariationInherentinSystemDesign.SomeVariationisduetoaFaultyperformanceoftheSystem(s).BasicConceptsEveryProcessprComponentsofMeasurementSystemEquipmentorGageTypeofGage:Attribute:go-nogo,visionsystemsVariable:calipers,probe,coordinatemeasurementmachinesUnitofMeasurement-discriminationAtleast1/10of6*processstandarddeviation(6s)Otherrules:atleast1/10oftoleranceOperator&OperatingInstructionsPartlocatingororientationschemeagagemustbeabletoconsistentlylocatethepartbeingmeasured.ComponentsofMeasurementSystTermsYouShouldKnow•Measurementsystem:

Thecollectionofoperations,procedures,gagesandpersonnelusetoobtainmeasurementsofworkpiececharacteristics•Gage:

Adeviceusedtoobtainmeasurements•Repeatability:

Repeatability(Precision)Thevariationinmeasurementobtainedwithonemeasurementinstrumentwhenusedbyoneoperatortomeasure.)anidenticalcharacteristiconthesamepart.(EV:EquipmentVariation•Reproducibility:

Thevariationintheaverageofthemeasurementsmadebydifferentoperatorsusingthesamemeasurementinstrumentwhenmeasuringidenticalcharacteristicsonthesamepart.(AV:AppraiserVariation)TermsYouShouldKnow•MeasureTermsYouShouldKnow•Bias:

Thedifferencebetweentheobservedaverageofmeasurementsandthereferencevalue.•PercentR&R:

Thepercentageofprocessvariationrelatedtothemeasurementsystemforrepeatabilityandreproducibility•Stability:

Thetotalvariationinthemeasurementsobtainedwithameasurementsystemonthesamemasterorpartswhenmeasuringsinglecharacteristicsoveranextendedtimeperiod.•Linearity:

Thedifferenceinthebiasvaluesthroughtheexpectedoperatingrangeofthegage.TermsYouShouldKnow•Bias:T1.AccuracyDifferencebetweenthetrueaverageandtheobservedaverage(trueaveragemaybeobtainedusingamoreprecisemeasuringtool)1.AccuracyDifferencebetween2.ReproducibilityVariationinaverageofmeasurementsmadebydifferentoperatorsusingthesamegagemeasuringthesamepart.AppraiserVariation(AV)2.ReproducibilityVariationin3.Repeatability(Precision)Randomvariationinmeasurementswhenoneoperatorusesthesamegagetomeasurethesamepartseveraltimes.EquipmentVariation(EV)3.Repeatability(Precision)Ra4.StabilityDifferenceintheaverageofatleast2setsofmeasurementsobtainedwithagageasaresultoftime.4.StabilityDifferenceinthePrecisionandAccuracyPrecisionandAccuracyAccuracyandStabilityMeasuresamepartsusingamorepreciseinstrument(Accuracy).

Measuresamepartsusingthesamegageatalaterdate(StabilityorDrift).AccuracyandStabilityMeasureMeasurementSystemVariablesMeasurementSystemVariablesPossibleSourcesofProcess

VariationPossibleSourcesofProcess

VaSourcesofMeasurementErrorSystematicVariations1.accuracy:impropercalibrationofequipment2.reproducibility:differentoperatorsusingsameequipmentwithdifferenttechniquesRandomVariations3.repeatability:(forexample,inconsistentpartlocating)PeriodicVariations4.stability:wear,deterioration,environmentalconditionsSourcesofMeasurementErrorSyTheGR&RDesignModelSupposemultipleoperators,measuremultiplepartsseveraltimeseach.Then:

Intermsofthegageperformance,between-operatorreproducibility

isduetotheoperatoreffectandtheoperator*partinteraction.Within-operator

repeatability

isfromthepureerrorterm.TheGR&RDesignModelSupposemTheComponentsofVarianceTheComponentsofVarianceMeasurementError–GageR&RMeasurementError–GageR&RAveragesANOVAanalysisbeginswiththecalculationofallrelevantaverages.Here’sanexample:AveragesANOVAanalysisbeginsTypesofGageErrorandAnalysis

Methods:Accuracy–GageAccuracy(Bias)StudyGageLinearityStudy.Repeatability&ReproducibilityGageR&R(Methods:X-bar/RangeorANOVA)RepeatedMeasurementStudyRepeatability–Static&DynamicStudyStability–RepeatedMeasurementsTypesofGageErrorandAnalysVariancePartitioningThetotalvarianceoftheGR&Rdataispartitionedintocomponentsaccordingtothemodel.Variancesadd,soallpartitionedpiecessumtothetotaldatavariance!VariancePartitioningThetotalTwoWayAnovaTableTwoWayAnovaTableGageR&RAcceptanceTodetermineacceptability,aratioistypicallyformedcomparinggagevariationtoeither:GageR&R%ofToleranceWidthGageR&R%ofTotalVariation6s-represents99.73%ofvaluesifnormaldistribution5.15s-represents99%ofvaluesifnormaldistributionGageR&RAcceptanceTodeterminCriteriaforEvaluatingGageR&RGageR&R%-TVorR&R%-ToleranceifR&R%is:<10%=measurementsystemisacceptable10-30%=measurementsystemmaybeacceptablebaseduponimportanceofapplication,gagecost,costofrepairs..>30%=measurementsystemneedsimprovementCriteriaforEvaluatingGageRConductingaGageR&RStudy1.Plantheapproach–Whatisnatureofoperatorandmeasurementinteraction?–Reproducibilitycanbenegligiblesometimes.2.Select3welltrainedoperators3.Select10partsfortest,Selectsamplepartsshouldrepresententirenormalproductionrange.(Prefercoverthedistributionof+/-4sigma)4.Repeatmeasureeachparts3times.5.Takemeasurementsinrandomorder.6.Takeblindmeasurement•Personmeasuringdoesn’tknowwhichpieceisbeingmeasured,whatpreviousmeasurementswere,orwhatotherappraisersfound.ConductingaGageR&RStudy1.ConductingaGageR&RStudy7.Recordallmeasurementsonworksheet.8.Calculatetrialrangeforeachpieceforeachoperatorandrecordvalues,calculateR&R(squarerootofthesumofthesquaresoftherepeatabilityandreproducibility).9.Keepthestandardparts&itsreadingfor“EquipmentCorrelation“purposeConductingaGageR&RStudy7.GuidelinesForGaugeR&RAcceptanceUnder10%Error:Acceptable10%~30%Error:MaybeAcceptabledependingontheimportanceoftheapplication.Over30%error:ImprovementisneededGuidelinesForGaugeR&RAccepGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyGaugeR&RStudyAnovaMethodExampleAnovaMethodExampleEquipmentCalibrationBySimpleLinearityModel(Y=mX+b)

EquipmentCalibrationSelectionofStandardUnitsSetupabout10pcsstandardunitswhichcancovertheoverallspreadofnormalproduction.Prefer2rejectunitbeyondupper/lowerspec.AgingallunitsFindstandardreadingSelectionofStandardUnitsSetRegressionAnalysis:EquipmentvsStandardMeasureStandardunitoneachindividualtestequipmentseveraltimes.TaketheaverageofmeasurementdataforeachunitRegressionAnalysis;EquipmentReadingvsStandardReading.Ifcorrelationcoefficient>90%,thencalculatetheslopeandoff-setpertestm/c.Ifcorrelationcoefficient<90%,findthereason.TestResult=ActualReadingXSlope+OffsetRegressionAnalysis:EquipmenMeasurementDataofStandardSets

@eachTestMachineMeasurementDataofStandardSRegressionAnalysisRegressionAnalysisAddTranslationKeyAfterCorrection=ReadingXSlope+OffsetTestresultbecomecloseramongtestmachines.Slope/OffsetperTestEquipmentAddTranslationKeyAfterCorreEquipmentLongTermStabilityTestEquipmentlongtermstabilitycanbecheckedbytesting1~3workingstandardunitspereachtimebeforeoperatorusethattestmachineandplotthetestresultsonaSPCchart.EquipmentLongTermStabilityComputingKappa

(GR&RTestForvisualinspector)ComputingKappa

(GR&RTestFKappaCoefficient(Cohen,1960)SzBpOtherni.pi.Sz106.53(78).39104120.6BP2228.14(15).0751060.3Other2126.03(2).0120.1n.j1305020200p.j.65.25.11Rater2Rater

1pi.xp.i .39 .075 .01•Highreliabilityrequiresthatthefrequenciesalongthediagonalshouldbe>chanceandoffdiagonalfrequenciesshouldbe<chance.•Usemarginalfrequencies/probabilitiestoestimatechanceagreement.

Proportionagreementobserved,po=∑ipii=1/n∑iniiProportionagreementexpectedbychance,pc=∑ipi.xp.i

po-

pc

1-pcKappa,K=po=.53+.14.03=.7pc=.39+.075+.01=.475

.7-.475

K=1-.475

=.429

K=1,perfectagreementK=0,chanceagreementK<0,agreementworsethanchance.KappaCoefficient(Cohen,1960KappaCoefficient(Cohen,1960)Proportionagreementobserved,po=∑ipii=1/n∑iniiProportionagreementexpectedbychance,pc=∑ipi.xp.iKappaCoefficient(Cohen,1960Select20goodand20badpartsHaveeachinspectorinspecteachofthepartsandrecordwhetherit“