training material for msa

TrainingMaterialforMEASUREMENTSYSTEMANALYSISContents:1)INTRODUCTIONFORMEASUREMENTSYSTEMANALYSIS2)GENERALMETHODSILLUSTRATIONFORMEASUREMENTSYSTEMANALYSIS1)VARIABLEGAGEANALYSISMETHOD1)THEAVERAGE-RANGEMETHOD2)THEANOVAMETHOD1)ATTRIBUTEGAGEANALYSISMETHOD1)SHORTMETHOD2)HYPOTHESISTESTANALYSIS3)SIGNALDETECTIONTHEORY4)LONGMETHOD3)ACCEPTABILITYCRITERIA4)CONCLUSION5)FOURMETHODSCOMPARISONIntroduction:BasicrequirementsbyQS-9000&TS16949•BaseonQS9000&TS16949requirements,allmeasurementsystemwhichwerementionedinQualityPlanshouldbeconductedMeasurementSystemAnalysis.MSARequirementIntroduction:ThecategoryofMeasurementSystem•Mostindustrialmeasurementsystemcanbedividedtwocategories,oneisvariablemeasurementsystem,anotherisattributemeasurementsystem.Anattributegagecannotindicatehowgoodorhowbadapartis,butonlyindicatesthatthepartisacceptedorrejected.ThemostcommonoftheseisaGo/No-gogage.VariableGageAttributeGage(Go/No-goGage)Introduction:WhatisameasurementprocessOperationOutputInputGeneralProcessMeasurementAnalysisValueDecisionProcesstobeManagedMeasurementProcessMeasurement:Theassignmentofanumericalvaluetomaterialthingstorepresenttherelationsamongthemwithrespecttoaparticularprocess.MeasurementProcess:Theprocessofassigningthenumericalvaluetomaterialthings.Introduction:WhatarethevariationsofmeasurementprocessIntroduction:WhatarethevariationsofmeasurementprocessMeasurement(Observed)Value=ActualValue+VarianceofTheMeasurementSystem2σobs=2σactual+σvarianceofthemeasurementsystem2Introduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:1.LocationVariation:Bias;Stability;LinearityBiasisthedifferencebetweentheobservedaverageofmeasurementsandareferencevalue.Biasisoftenreferredtoasaccuracy.ItisasystematicerrorcomponentofthemeasurementsystemIntroduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:1.LocationVariation:Bias;Stability;LinearityStability(Alias:Drift):Stabilityisthetotalvariationinthemeasurementsobtainedwithameasurementsystemonthesamemasterorpartswhenmeasuringasinglecharacteristicoveranextendedtimeperiod.Astablemeasurementprocessisinstatisticalcontrolwithrespecttolocation.StabilityIntroduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:1.LocationVariation:Bias;Stability;LinearityLinearityisthedifferenceinthebiasvaluesthroughtheexpectedoperatingrangeofthemeasurementinstrument.Itisasystematicerrorcomponentofthemeasurementsystem.LinearityIntroduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:2.WidthVariation:Repeatability;Reproducibility;GageR&RRepeatabilityisthevariationinmeasurementsobtainedwithonemeasurementinstrumentwhenusedseveraltimeswhilemeasuringtheidenticalcharacteristiconthesamepartbyanappraiser.ItisaWithin-systemvariation,commonlyreferredtoasE.V.---EquipmentVariation.RepeatabilityIntroduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:2.WidthVariation:Repeatability;Reproducibility;GageR&RReproducibilityisthevariationintheaverageofthemeasurementsmadebydifferentappraisersusingthesamegagewhenmeasuringtheidenticalcharacteristicsofthesamepart.Itisbetween-systemvariation,commonlyreferredtoasA.V.---AppraiserVariation.ReproducibilityIntroduction:Wheredoesthevariationofmeasurementsystemcomefrom?•TheFiveCharacterizationsofMeasurementSystem:2.WidthVariation:Repeatability;Reproducibility;GageR&RGageR&RmeansGagerepeatabilityandreproducibility,whichcombinedestimateofmeasurementsystemrepeatabilityandreproducibility.ThiscombinedmeasurementerrortheniscomparedwiththeprocessoutputvariabilitytocomputethegagepercentageR&R(%R&R).The%R&Risthebasisformakingajudgmentofwhetherthemeasurementsystemisgoodenoughtomeasuretheprocess.AnalysisTechniques:•CurrentlytherearethreetechniquesforvariablemeasurementsystemandfourtechniquesforattributemeasurementsystemanalysiswererecommendedbyAIAGMSAReferenceManual.•RangeMethod•Average-RangeMethod•ANOVA•ShortMethod•LongMethod•HypothesisTestAnalyses•SignalDetectionTheory•Followingsaresomepracticalexamplestoillustratehowtoperformfourmethodsrespectively.VariableGageAttributeGageAnalysisTechniques:PreparationbeforeMSA1.Theapproachtobeusedshouldbeplanned.2.Thenumberofappraisers,numberofsampleparts,andnumberofrepeatreadingsshouldbedeterminedinadvance.3.Theappraisersshouldbeselectedformthosewhonormallyoperatetheinstrument.4.Thesamplepartsmustbeselectedfromtheprocessandrepresentitsentireoperatingrange.5.Theinstrumentmusthaveadiscriminationthatallowsatleastone-tenthoftheexpectedprocessvariationofthecharacteristictobereaddirectly.6.Themeasurementprocedureshouldbedefinedinadvancetoensuretheconsistentmeasuringmethod.AnalysisTechniques:VariableGageAnalysis1.GeneralGageR&RStudy:TheAverageandRangeMethodTheANOVAMethodThecommonstepforconductingGageR&Rstudy:1.Verifycalibrationofmeasurementequipmenttobestudied.2.Obtainasampleofpartsthatrepresenttheactualorexpectedrangeofprocessvariation.3.Add