FMEA失效模式和效果分析美国宇航局

1NASALewisResearchCenterr1TOOLSOFRELIABILITYANALYSIS--IntroductionandFMEAs(09)DEDUCTIVEPROCEDURES(Top-DownAnalysis)INDUCTIVEPROCEDURES(Bottom-UpAnalysis)PickUpperLevelFailureinComponentFlowdowncausesDetermineFailureModesofLowerLevelComponents.SummarizeupwardRELIABILITYANALYSISPROCEDURESRELIABILITYANALYSISPROCEDURESINDUCTIVEMETHODSDEDUCTIVEMETHODSHARDWAREFAILURESHUMANINTERACTIONERRORSHARDWAREANDHUMANERRORSRELIABILITYANALYSISFAILUREMODEANDEFFECTSANALYSIS(FMEA)HUMANFACTORSANALYSISFAULTTREEANALYSIS(FTA)EVENTTREEANALYSIS(ETA)PROBABILISTICRISKASSESSMENTCRITICALITEMSLIST(CIL)4NASALewisResearchCenterr1FAILUREMODEANDEFFECTANALYSIS(09con’t)5NASALewisResearchCenterr1DEFINITION•Amethodologytoanalyzeanddiscover:(1)allpotentialfailuremodesofasystem,(2)theeffectsthesefailureshaveonthesystemand(3)howtocorrectandormitigatethefailuresoreffectsonthesystem.[Thecorrectionandmitigationisusuallybasedonarankingoftheseverityandprobabilityofthefailure]6NASALewisResearchCenterr1BenefitsofFMEA•FMEAisoneofthemostimportanttoolsofreliabilityanalysis.Ifundertakenearlyenoughinthedesignprocessbyseniorlevelpersonnelitcanhaveatremendousimpactonremovingcausesforfailuresorofdevelopingsystemsthatcanmitigatetheeffectsoffailures.•Itprovidesdetailedinsightintothesystemsinterrelationshipsandpotentialsforfailure.•FMEAandCIL(CriticalItemsList)evaluationsalsocrosschecksafetyhazardanalysesforcompleteness.7NASALewisResearchCenterr1BACKGROUND•Thefailuremodeandeffectsanalysis(FMEA)isthemostwidelyusedanalysisprocedureinpracticeattheinitialstagesofsystemdevelopment.•TheFMEAisusuallyperformedduringtheconceptualandinitialdesignphasesofthesysteminordertoassurethatallpossiblefailuremodeshavebeenconsideredandthatproperprovisionshavebeenmadetoeliminateallthepotentialfailures.8NASALewisResearchCenterr1OBJECTIVES:•Beabletoanswer(orperform):•Explainterminology:FMEA,CIL,REDUNDANCY,COMMONMODEFAILURE,etc.•WhatarethebenefitsofFMEAandwhenshouldtheybeappliedinthedesignprogram?•Beableevaluatelevelsofcriticality&redundancy.•BeabletoperformacomponentsFMEAandasystemFMEA.•KnowhowtoapplytheresultsofaFMEA.9NASALewisResearchCenterr1FAILUREMODEANDEFFECTANALYSIS•PURPOSE/TYPES/USES.•PROCEDURE.•DATAREQUIREMENTS&TERMS/TYPES.•WHYANDHOWDOTHINGSFAIL?•PERFORMINGAFMEA.•ADDITIONALINFORMATION.–CriticalItemsListSystemEngineering:FMEAFMEA;FMEAINITIALCONCEPTFMEAEVALUATEDESIGN&REV;PREVENTIONS&DETECTIONSCoDRPDRCDRCONCEPTDESIGNPRELIM.DESIGNFINALDESIGNCOMPONENTS/ASSY,TEST&INSPECTIONPRODUCTIONINSPECTIONACCEPTANCETESTSFMEAFINAL&MAINTFMEA.ACTIONSAGREEDTO,IMPLEMENTSYS.TESTFMEAEVALforADEQUACY,FAULTDIAGNOSIS11NASALewisResearchCenterr1TYPES•Functional•Hardware•FMEAwithCriticalityAnalysis(FMECA)/CriticalItemsList•Othervariations.12NASALewisResearchCenterr1USES--ShortTerm•Identifycriticalorhazardousconditions.•Identifypotentialfailuremodes•Identifyneedforfaultdetection.•Identifyeffectsofthefailures.13NASALewisResearchCenterr1USES--Longterm.•Aidsinproducingblock-diagramreliabilityanalysis•Aidsinproducingdiagnosticchartsforrepairpurposes.•Aidsinproducingmaintenancehandbooks.•Designofbuilt-intest(BIT),failuredetection&redundancy.•Foranalysisoftestability.•Forretentionasformalrecordsofthesafetyandreliabilityanalysis,tobeusedasevidenceinproductsafetylitigation.14NASALewisResearchCenterr1PROCEDURE•Getanoverviewofthesystem:–Determinethefunctionofallcomponentry.–Createfunctionalandreliabilityblockdiagrams.–Documentallenvironmentsandmissionsofsys.•IDallpotentialfailuremodesofeachcomponent.•Establishfailureeffectonthenextlevelofthesys.–Determinefailuredetectionmethods.–Determineifcommonmodefailuresexits.•Determinecriticalityofthefailure,ranking&CIL.–DevelopCIL–Correctiveactions/retentionrationale.•Providesuitablefollow-uporcorrectiveactions.15NASALewisResearchCenterr1PROCEDURE-FLOWCHARTPERFORMFMEA,IDFAILUREMODESDESIGNGETSYSTEMOVERVIEWESTABLISHFAILUREEFFECTDETERMINECRITICALITYREVISEDESIGNTERMS:FMEAWORKSHEETPage___of____Date:__________Title:_________________________________System:______________________________Analyst:_____________DescriptionFunctionFailureModeCauseofFailureEffectofFailureCorrectiveActionDetectionCrit./Rank17NASALewisResearchCenterr1FAILURETERMSREVIEW:THEPROCESSOFFAILUREFAILUREMODEFAILURECAUSEFAILUREMECHANISMFAILURESTRESSESOBSERVEDPROBLEM18NASALewisResearchCenterr1WHYDOTHINGSFAIL?(FailureMechanisms)•fatigue/fracturematerialremoval•structuraloverloadradiation•electricaloverload________________•wear(lubefailure)________________•wear(contamination)________________•wear________________•sealfailure________________•chemicalattack________________•oxidation________________19NASALewisResearchCenterr1HOWDOTHINGSFAIL?(FailureMode)•Inwhatwayscantheyfail?•Howprobableisthisfailure?•Dooneormorecomponentsinteracttoproduceafailure?•Isthisacommonfailure?•Whoisfamiliarwiththisparticularitem?•PROBLEM--VALVE(P)OPTIONALPROB:CHEMMICROEXP20NASALewisResearchCenterr1Review--PURPOSEOFFMEA???•Thepurposeistoidentifythedifferentfailuresandmodesoffailurethatcanoccuratthecomponent,subsystem,andsystemlevelsandtoevaluatetheconsequencesof