FMEA失效模式及其影响分析

1FailureModeandEffectAnalysis失效模式及其影响分析ModuleObjectives课程目的•DescribeFMEAprinciplesandtechniques.n描述FMEA的法则及技巧。•Summarizetheconcepts,definitions,applicationoptionsandrelationshipswithothertools.•摘要概念、定义、应用的选择和其他工具的关联。•PerformaFMEA•执行一个FMEA。FMEA:FailureModesandEffectsAnalysisFMEAisasystematicapproachusedtoexaminepotentialfailuresandpreventtheiroccurrence.Itenhancesourabilitytopredictproblemsandprovidesasystemofranking,orprioritization,sothemostlikelyfailuremodescanbeaddressed.FMEA是用来检查潜在失效和预防它再次发生的系统性方法.它增强了我们预测问题的能力,并提供了一个排序或区分优先次序的系统,因而使得最可能的失效模式得以确定.FMEAisgenerallyappliedduringtheinitialstagesofaprocessorproductdesign.Brainstormingisusedtodeterminepotentialfailuremodes,theircauses,theirseverity,andtheirlikelihoodofoccurring.InSixSigma,weapplyFMEAtoknowfailuremodes.Ourmaininterestsarethecauseandlikelihoodofoccurrence,forwhichwehaveactualdataanddonotneedtorelyonbrainstorming.FMEA通常应用在工艺及产品设计的初期，自由讨论决定潜在失效的模式、原因、严重度及发生的可能性。在6S中，我们应用FMEA去了解失效的模式。我们主要感兴趣的是原因及发生的可能性。FMEAisalsoavaluabletoolformanagingtasksduringdefect/failurereductionprojects.FMEA也是一个在失效缩小的管理任务的有价值的工具。FMEADefinitionofFMEA定义1.recognizeandevaluatethepotentialfailuremodesandcausesassociatedwiththedesigningandmanufacturingofanewproductorachangetoanexistingproduct.认识和评估新产品的设计和制造时或对现有产品做出改变时相关的潜在失效模式和原因2.identifyactionswhichcouldeliminateorreducethechanceofthepotentialfailureoccurring,确定消除或减少潜在失效发生机会的行动3.documenttheprocess.使过程形成文件FMEAisasystematicdesignevaluationprocedurewhosepurposeisto:是系统的设计评估程序Failuretoperformadefinedfunction执行既定功能的失效Somethingoccurringthatyoudon‘texpect,orwant发生了你不希望或不想要的事情Wrongapplication应用错误AFailureModeis...失效模式是……FMEAUsebyBlack/Brown/GreenBeltsToidentifypotentialfailuremodesandratetheseverityoftheireffectsToidentifycriticalcharacteristicsandsignificantcharacteristicsTorankpotentialdesignandprocessdeficienciesTohelpallofusfocusoneliminatingproductandprocessconcernsandpreventproblemsfromrecurringReducetheproductdevelopmenttimingandcostBackgroundDevelopedinearly60’sbyNASAto“fail-proof”Apollomissions.Adoptedinearly70’sbyUSNavy.Bylate80’s,automotiveindustryhadimplementedFMEAandbeganrequiringsuppliersdothesame.Liabilitycostswerethemaindrivingforce.Usedsporadicallythroughoutindustryduring1980’s.AdoptedbyMSIin?SixSigmaisthecatalyst.NASAusedFMEAtoidentifySinglePointFailuresonApolloproject(SPF=noredundancy&lossofmission).Howmanydidtheyfind?420andwethoughtwehadproblems!TypesofFMEA’sSYSTEMDESIGNPROCESSSystemFMEAisusedtoanalyzesystemsandsubsystemsintheearlyconceptanddesignstages.DesignFMEAisusedtoanalyzeproductsbeforetheyarereleasedtoproductionProcessFMEAisusedtoanalyzemanufacturing,assemblyandadministrativeprocessesWhenistheFMEAStarted?“Dothebestyoucanwithwhatyouhave”ASEARLYASPOSSIBLE!Guideline:WhentoStart???Whennewsystems,productsandprocessesarebeingdesignedWhenexistingdesignsandprocessesarebeingchangedWhencarry-overdesignsorprocesseswillbeusedinnewapplicationsorenvironmentsAftercompletingaProblemSolvingStudy,topreventrecurrenceofaproblemBeginningandEndSTARTCOMPLETESYSTEMAftersystemfunctionsaredefined,beforespecifichardwareisselectedWhentheprojectisturnedovertodesignDESIGNAfterproductfunctionsanddesignconceptsaredefinedbutbeforethedesigniscompleteWhenfinaldrawingsarereleasedPROCESSWhenpreliminarydrawingsareavailablebutbeforetoolingdesigniscompletedWhentheproductreachesendoflifeorisremovedfromproductionEffectofFMEAonProcessandDesignchangesDesignStartDevelopmentProductionReleaseProductionTimeNoofEngineeringChangesTraditionalapproachFMEAapproachProcessFMEAFormPotentialFailureModeandEffectsAnalysisPFMEA#:ProcessResponsibility:PreparedBy:ProcessName:AffectedProducts:#ProcessFunction(Step)PotentialFailureModes(ProcessDefects)PotentialEffectsofFailures(KPOVs)SEVPotentialCausesofFailures(KPIVs)OCCCurrentProcessControlsDETRPNRecommendActionsWhatistheprocessstepWhatisthekeyprocessinputInwhatwaydoesthekeyinputgowrongHowsevereistheeffecttocustomerWhatcausesthekeyinputtogowrongHowoftendoescauseoccurWhataretheexistingcontrols&procedures(inspection&test)thatpreventwiththecauseorFailureModeHowwellcanyoudetectcauseotFMWhataretheactionsforreducingtheoccurrenceoftheCause,orimprovingDetection?ShouldhaveactionsonlyonhighRPN'soreasyfixes.CPotentialOProcessPotentialPotentialSlCause(s)cFailureEffect(s)ofeaMechanism(s)cFunctionModeFailurevsofFailureusrPoortraining3Failtodetectintheprocessofincominginspection2Misunderstandingofdefectdefinition2OP100INCOMINGINSPECTION-PORTFITTING/ToverifyportsmadetoprintFailtoidentifydamagedportPoorPrintbilityPoorgagePlacementWeldingprocessfailureSealingprocessfailureFuctiontestinfailure8ElementsofFMEAFailureModeAnywayinwhichaprocesscouldfailtomeetsomemeasurableexpectation.EffectAssumingafailuredoesoccur,describetheeffects.Listseparatelyeachmaineffectonbothadownstreamoperationandtheenduser.SeverityUsingascaleprovided,ratetheseriousnessoftheeffect.10representsworstcase,1representsleastsevere.CausesThisisthelistofcausesand/orpotentialcausesofthefailuremode.OccurrenceThisisaranking,onascaleprovided,ofthelikelihoodofthefailu