失效模式及後果分析.ppt

FMEA失效模式及后果分析,OVERVIEWOFTHECHRYSLER/FORD/GMPOTENTIALFAILUREMODEANDEFFECTSANALYSISREFERENCEMANUAL克莱斯勒,福特,通用的潜在失效模式及效果分析参考手册概述,FMEA失效模式及后果分析,ADDITIONALASSISTANCE其他帮助来源Chrysler克莱斯勒ProcurementandSupply(SupplierDevelopment)采购和供应(供应商开发).Ford福特CustomerDivisionSupplierTechnicalAssistance(STA)客户部供应商技术支持.GM通用ProcuringDivisionSupplierDevelopmentcontact采购部供应商开发Forspecifictechnicalquestions,contacttheappropriateresponsibleengineer(workwithyourcustomer).如有特殊问题,可以与相应的工程师(与你们顾客一起工作的)联系.,FMEA失效模式及后果分析,History历史May1991-SupplierQualityRequirementsTaskForceSupplierAdvisoryCouncilidentifiedseveraltoolsthatwouldbenefitfromstandardization.在1991年5月,供应商质量要求行动小组供应商顾问委员会明确了几种工具,并通过标准化使大家受益.SupplierQualityRequirementsTaskForceassessedfeasibilityandselectedseveralprojectsforcommunization,includingFMEA.供应商质量要求行动小组评估了其可行性并选择了几个项目以便沟通,其中包括FMEA.FMEAWorkGroupcompletedReferenceManualinDec.1992在1992年12月,FMEA工作小组完成了参考手册的编写.Early1993-FMEAReferenceManualapproved在1993年年初,FMEA参考手册被认可.Mid1993-Trainingdeveloped1993年中期,建立了相关培训.Phasedinduring3rdquarter1993,accordingtoindividualcustomerrequirements.根据个别顾客要求,在1993年第三季度逐步执行.February1995updatedandreissued1995年2月更新并再版.,FMEA失效模式及后果分析,PLEASENOTE请注意FMEAtrainingofferedbyFord(FairlaneTrainingthosethat:有三种设计控制方法可考虑，它们是：1)Preventthecause/mechanismorfailuremode/effectfromoccurring,orreducetheirrateofoccurrence防止起因/机理或失效模式/后果的出现，或减少它们出现率2)Detectthecause/mechanismandleadtocorrectiveactions查出起因/机理并导致找到纠正措施3)Detectthefailuremode查明失效模式,DFMEA设计失效模式及后果分析,(17)Detection(D)AbilityofaCurrentDesignControltoidentifyapotentialcauseSuggestedEvaluationCriteria:,DetectionCriteria:likelihoodofDetectionbyDesignControlRankingAbsoluteDesignControlwillnotand/orcannotdetectapotentialcause/10Uncertaintymechanismandsubsequentfailuremode;orthereisnoDesignControl.etc,Pleaserefertopage19oftheFMEAMANUAL.,DFMEA设计失效模式及后果分析,(17)不易探测度(D)用现行设计控制方法来探测潜在失效原因能力的评价指标推荐的评价准则：(请参考FMEA手册的第19页),DetectionCriteria:likelihoodofDetectionbyDesignControlRankingAbsoluteDesignControlwillnotand/orcannotdetectapotentialcause/10Uncertaintymechanismandsubsequentfailuremode;orthereisnoDesignControl.etc,DFMEA设计失效模式及后果分析,(18)RiskPriorityNumber(RPN)风险顺序数(RPN)RPN=S*O*D风险顺序数是严重度数(S),频度数(O),和不易探测度数(D)的乘积Usedasaguidetohelprankprocessconcerns用来对过程中所担心的事项排序Golfscoreconcept(Lowerisbetter)就象高尔比赛得分那样,数值越小越好Thereareno“threshold”values没有标准分值Specialattentionshouldbegivenwhenseverityishigh(asdefinedbytheteam,includingtheCustomer)由可行性小组(包括顾客)所定义的严重度高时要给予特别关注,DFMEA设计失效模式及后果分析,(18)风险顺序数(RPN),Likethechart,sorttheRPN,andtakecorrectiveactionstoreducethehigherones;就象图表所示,先排列出所有的风险顺序值,然后优先解决高分值问题,DFMEA设计失效模式及后果分析,(19)RecommendedAction(s)建议措施IntentistoreduceSeverity,Occurrence,and/orDetectionrankings目的是为了减少严重度，出现频次，和/或不易探测度Examples例如DOE试验设计RevisedTestPlan修改试验计划RevisedDesign修改设计RevisedMaterialSpecification修改材料性能要求,DFMEA设计失效模式及后果分析,(20)Responsibility/TargetDate责任/目标日期(21)ActionsTaken采取的措施(22)ResultingRPN纠正后的RPN,PFMEA过程失效模式及后果分析,DevelopmentofaProcessFMEA过程FMEA的开发AssembleTeam成立小组AssignResponsibilities职责分配leader组长data-gathering数据收集recorder记录员Processflowdiagramisvaluableatthispoint在这个时候,过程流程图是非常有用的.BeginFMEA开始FMEA工作,PFMEA过程失效模式及后果分析,HeaderInformation前面的信息Items(1)through(8)从(1)至(8)项EssentiallythesameasDesignFMEA内容基本上与DFMEA一样.,PFMEA过程失效模式及后果分析,(9)ProcessFunction/Requirements过程功能/要求Enterdescriptionandpurpose输入功能描述和目的.Beasconciseaspossible尽可能简要.(10)PotentialFailureMode潜在失效模式“themannerinwhichtheprocesscouldpotentiallyfailtomeettheprocessrequirementsand/ordesignintent.”“是指过程可能发生的不满足过程要求和/或设计意图的形式.Adescriptionofnon-conformance是对不符合的一个描述.Assumeincomingpartsarecorrect假定提供的部件都是合格的.Remembertoconsidersubsequentoperations.记得要考虑下道工序.,PFMEA过程失效模式及后果分析,(11)PotentialEffect(s)ofFailure潜在失效后果Effectoffailuremodebasedonwhatcustomermightnotice/experience失效模式后果是依据顾客可能注意到的或所经历的.Includessubsequentprocessoperations应包括下道工序操作.(12)Severity严重度Theseriousnessoftheeffectofthepotentialfailuremode是指潜在失效模式后果的严重程度.SuggestedEvaluationCriteria(PleaserefertoPage35oftheFMEAMANUAL.)推荐的评价准则.(请参考FMEA手册)SimilartoDesignFMEA,butalsoconsidersoperations/subsequentprocessoperations.与DFMEA一样,但应考虑操作或下道工序操作.,PFMEA过程失效模式及后果分析,(13)Classification分级SimilartoDesignFMEA与DFMEA一样.Ifclassificationismade,notifyresponsibledesignengineer.如果确定了某一分级,应通知设计主管工程师.Ifclassificationismade,mustbeaddressedintheProcessControlPlan.如果确定了某一分级,它一定要包括在过程控制计划中.(14)PotentialCause(s)/Mechanism(s)ofFailure潜在失效起因/机理“howthefailurecouldoccur.”“失效是怎样发生的.”Describedintermsofsomethingthatcanbecorrected/controlled应用术语来形容那些可纠正或控制的机理或起因RequiresdeterminationofRootCause要求要决定根本起因.,PFMEA过程失效模式及后果分析,(15)Occurrence频度(O)Ifavailable,statisticaldatashouldbeused如果必要,可应用数据统计.SuggestedEvaluationCriteria:推荐评价标准.,PleaserefertoPage39oftheFMEAMANUAL.请参考FMEA手册第39页,PFMEA过程失效模式及后果分析,(16)CurrentProcessControls现行过程控制TherearethreetypesofProcessControls/featurestoconsider;thosethat:可以考虑三种过程控制方法/特点,即:Preventthecause/mechanismorfailuremode/effectfromoccurring,orreducetheirrateofoccurrence.阻止失效起因/机理或失效模式/后果的发生,或减小其发生率.Detectthecause/mechanismandleadtocorrectiveactions.查明起因/机理并找到纠正措施.Detectthefailuremode.查明失效模式.Mayoccuratthisorsubsequentoperations可能会出现在这个或下个工序.,PFMEA过程失效模式及后果分析,(17)Detection不易探测度(D)Assumefailurehasoccurred假定失效已经发生.AssesscapabilitiesofallCurrentProcessControls评价所有现行过程控制方法的能力.SuggestedEvaluationCriteria推荐评价标准,PleaserefertoPage41oftheFMEAMANUAL请参考FMEA手册第41页,PFMEA过程失效模式及后果分析,(18)RiskPriorityNumber(RPN)风险顺序数(RPN)RPN=S*O*D风险顺序数是严重度数(S),频度数(O),和不易探测度数(D)的乘积Usedasaguidetohelprankprocessconcerns用来对过程中所担心的事项排序Golfscoreconcept(Lowerisbetter)就象高尔比赛得分那样,数值越小越好Thereareno“threshold”values没有标准分值Specialattentionshouldbegivenwhenseverityishigh(asdefinedbytheteam,includingtheCustomer)由可行性小组(包括顾客)所定义的严重度高时要给予特别关注,PFMEA过程失效模式及后果分析,Likethechart,sorttheRPN,andtakecorrectiveactionstoreducethehigherones;就象图表所示,先排列出所有的风险顺序值,然后优先解决高分值问题,PFMEA过