FMEA失效模式和效果培训教材

本资料来源FailureModeandEffectAnalysis(FMEA)

失效模式和效果分析LearningObjectives

学习目的GiveageneralintroductiontoFMEAprinciples.

介绍FMEA的基本原理.

Provideastep-by-stepguidanceinperformingFMEA

为实施FMEA提供指导.TheobjectiveofthisChapteristo本章节的目的是FMEADefinitionofFMEA

FMEA定义(I)FMEA:FailureModeandEffectsAnalysisFMEA：失效模式和效果分析Aprocedureinwhicheachpotentialfailuremodeineverysub-itemofanitemisanalyzedtodetermineitseffectonothersub-itemsandontherequiredfunctionoftheitem.FMEA是一个过程，在这个过程中对每个分项目的潜在失效模式进行分析，确定失效模式对于其他分项目和主项目的功能的影响Takenfrom“TheCertifiedQualityEngineerHandbook”ASQDefinitionofFMEA

FMEA定义(II)FMEA:FailureModeandEffectsAnalysisFMEA：失效模式和效果分析FMEAisastructuredanalysistoanticipatethe

potentialfailuresofadesignorprocessbeforetheyoccur.Allaspectsofeachpotentialfailurearestudiedtoidentifythemosteffectivepreventiveactions.FMEA是结构化的分析方法。用它在设计或过程的失效模式发生之前就预见潜在的失效.然后全面分析失效的各方面并识别最有效的预防措施.AnotherDefinitionForFMEA(III)FMEAisasystematicapproachusedtoexamine

potentialfailuresandpreventtheiroccurrence.Itenhancesanengineer’sabilitytopredictproblemsandprovidesasystemofranking,or

prioritization,sothe

mostlikelyfailuremodescanbeaddressedFMEA

是用来调查潜在失效及预防其再发生的系统化方法。这方法可以帮助提高工程师预知问题的能力，提供一套依风险大小顺序排列失效的系统，以让我们能针对最可能的失效模式先采取对策DefinitionofFMEA

FMEA定义Identifyandevaluate

thepotentialfailuremodes

ofaproduct/processandtheeffectsofthatfailure

识别和评估一个产品或过程的潜在失效模式及其影响；2.Listdowntheactionswhichcouldeliminateorreducethechanceofthepotentialfailureoccurring

确定能排除或减少潜在失效发生的机率的措施；3.

Documentalltheelementsforreviewandaction

文件化整个过程。AnFMEAcanbedescribedasasystematicgroupofactivitiesintendedto:FMEA是一系列系统化的活动，其目的是

：PropertiesofFMEA

FMEA的特点FMEAbeginswithadefinitionofallthe

functionsaprocessissupposedtoperform.FMEA开始于一个过程所有功能的定义ManufacturingEngineer制造工程师SupplierQuality供应商质量DesignEngineer设计工程师ProgramManagement程序管理Production产品ReliabilityEngineer可靠性工程师Teamwork团队力量

FMEAmustbeperformedbyateaminordertoensureitseffectivenessFMEA须由小组进行,以确保其有效PropertiesofFMEA

FMEA的特点ThePurposeofFMEA

FMEA的目的Toidentifypotentialfailuremodesandratetheseverityoftheireffects识别潜在失效模式并评估他们影响的严重性Toidentifycriticalcharacteristicsandsignificantcharacteristics识别关键特性和重要特性Torankpotentialdesignandprocessdeficiencies评估潜潜在的的设计计和工工序不不足Reducetheproductdevelopmentcycle-timeandhencecost减少产产品开开发时时间和和成本本Tofocusoneliminatingandpreventingproductandprocessproblems聚焦于于产品品和工工序问问题的的消除除，并并防止止问题题再次次发生生ThePurposeofFMEAFMEA的目的的Background背景Bylate80’’s,FMEAisusedbyautomotivemanufacturersandtheirsupplierstoreducetheliabilitycost.到80年代末末，汽汽车工工业和和他们们的供供货商商也开开始实实施FMEA，藉此此减低低责任任成本本Developedinearly60’’sbyNASAto““fail-proof””Apollomissions.60年代初初，由由美国国太空空空署署在阿阿波罗罗任务务中发发展起起来的的。Adoptedinearly70’’sbyUSNavytodevelopMIL-STD-1629.70年代初初，被被美国国海军军采用用。TypesofFMEAFMEA的类型型Itiswidelyusedinbothmanufacturingandtransactionalareas在制造造和服服务流流程中中都可可以使使用SYSTEM系统FMEASystemFMEAisusedtoanalyzesystemsandsubsystemsintheearlyconceptualdesignstages.SFMEA是用来来在早早期构构思设设计阶阶段分分析系系统与与子系系统DESIGN设计FMEADesignFMEAisusedtoanalyzeproductsbeforetheyarereleasedtoproductionDFMEA是用来来在生生产发发布前前分析析产品品。PROCESS过程FMEAProcessFMEAisusedtoanalyzemanufacturing,assemblyandadministrativeprocessesPFMEA用来分分析制制造、、装配配和管管理过过程WhenShouldWeImplementFMEA?应在什什么时时候实实施FMEA？WeShouldStartFMEA我们应应开始始FMEAASEARLYASPOSSIBLE越早越越好！！StartandEndprocess开始和结束束SYSTEM系统DESIGN设计PROCESS过程START开始Aftersystemfunctionsaredefined,beforespecifichardwareisselected当系统功能定义后，在特殊硬件选定前。Afterproductfunctionsanddesignconceptsaredefined

butbeforethedesigniscompleted当产品功能和设计概念定义后，在设计完成前Whenpreliminarydrawingsareavailablebutbefore

toolingdesigniscompleted当初始图纸已应用，但在工装设计完成前END结束Whentheprojectisturnedovertodesign当项目转化成设计时Whenfinaldrawingsarereleased当最终图纸发布前。Whentheproductreachesendoflifeorisremoved

fromproduction当该产品寿命终止或不再生产ProcessFMEAFormat过程FMEA格式PFMEA图表产品：:FMEA编号：过程FMEA过程/操作；第页页共页页计划编制参参考：:日期：编制：城市过程描述潜在失效模模式S潜在失效的起因O现行控制DRPN优先措施责任人和完成日期采取的措施施措施结果潜在失效后后果功能SODRPN探测度频度数严重度RPN=SxOxD纠正措施ProcessFailureMode过程失效模模式Itisthemannerinwhichtheprocesscouldfailtoperformitsintendedfunction.潜在失效模模式是过程程可能发生生的不满足足其原有功功能的形式式Thefailuremodeofaparticularprocessstepcouldbeacausetoasubsequentsteporaneffectofthefailureinapreviousoperation.某一工序的的失效模式式可能是后后续操作（（下道工序序）的起因因，或前期期操作（前前道工序））相关的潜潜在失效的的后果。ProcessFailureMode过程失效模模式EffectforPreviousOperationistheCauseforNextOperation前工序的的的后果，是是后工序的的原因PREVIOUSOPERATION前道工序NEXTOPERATION下道工序EFFECT后果FAILUREMODE失效模式CAUSE原因PotentialCauses潜在原因ProcessFMEAconsidersprocessvariabilitydueto:5M+E过程FMEA考虑是由于于如下原因因造成的过过程变异性性:5M+EMACHINE机器ENVIRONMENT环境MEASUREMENT测量MAN人员METHOD方法MATERIAL物料CurrentControls现行控制CurrentProcessControlsaredescriptionsofthecontrolsthat现行控制是是对以下控控制的描述述eitherpreventtotheextentpossiblethefailuremodefromoccurring尽可能的防防止失效模模式的发生生ordetectthefailuremodeshoulditoccur或当失效模模式发生时时能够查觉觉它Assessmentoftheabilitytodetectthefailurebeforemovetothenextprocessorshippedtothecustomer.在产品制移移交下道工工序前或交交付给客户户前，对查查觉失效能能力的评估估CurrentControls现行控制Capabilityofallcontrolsintheprocesstopreventescapes过程中预防防坏品流出出的所有控控制能力Testing检测SPC统计过程控控制GaugeR&R量化重复性性和再现性性ProcessCapabilityStudy过程能力分分析SampleInspection抽样检验ProcessAudit过程审核CurrentControls现行控制ScoringCategories评分类别Scoresareassignedtothefollowing3categories:对以下3类进行评分分：SEVERITY(S)严重度Theseriousnessofthepotentialfailuremodetothecustomer.Thecustomerincludeslocalsystem,nextlevelandenduser.Severityappliestotheeffectonly.潜在失效模式对客户的严重度。这里所指的客户包括系统，下个工序和最终用户。严重度只适用于结果OCCURRENCE(O)发生频率Howfrequentaspecificcausewilloccurandresultinaspecificfailuremode.Theoccurrencerankingnumberhasameaningratherthanavalue.造成某种失效模式的某个原因多长时间发生一次。发生频率的重点并不在于它的得分，而是它的意义DETECTION(D)可探测度Probabilityofthecurrent/proposedcontrolmechanismtodetectandidentifythefailuremode是指当前或将要用来探测或鉴别失效模式的控制设备能多探测出失效模式的概率RiskPriorityNumber风险优先指指数RPN=OxSxD/EWhere:其中O--Occurrencex发生频率S--Severityx严重性D--Detection可探测性orE–Effectiveness有效性ShortcomingsofRPNRPN的缺点A845160B485160SAMERESULT!相同的结果果FailureMode失效模式S严重度O发生频度D/E有效性RPN风险优先指指数ActionPriority措施优先级级别ABCDOver200100-19926-991-25PRIORITY优先级别RPNRANGERPN范围Thisisforreferenceonly仅供参考FMEABestAppliedFor

FMEA最适合应用用于什么？？Thereisachangefrompreviousversion同以前相比比有变化的的Processcontrolishighlyoperatordependent过程控制主主要依赖于于操作员Newtechnologyintroduced包含新技术术Haveahighdegreeofvariation变异较多的的Thereisachronicallyproblem长期存在问问题的FMEAisbestappliedforthefollowingdesignorprocesses...FMEA最适合应用用于以下设设计或过程程……HowIsFMEAAppliedinSixSigmaFMEA在6Sigma中的运用FMEAinputistheprocessflowchartFMEA的输入是流程图。Input输入ProcessFlowchart流程图Process过程FMEAOutput输出HighPriorityFailureModes&CausesofFailure高优先级失失效模式及及失效原因因FMEAisananalyticalprocess.FMEA是一个分析的过程。。FMEAoutputisprioritizedkeyprocessinputvariables.FMEA的输出是一一个有优先级级的失效模式和失失效原因。。FMEAExample-Step1FMEA例子-步骤11.Fillintheheaderinformation填写标题信信息(1).Describetheprocess流程描述(2).NumbertheFMEA编号(3).IdentifytheBB/GB确定人选(4).Identifypagenumbers确定页数(5).Listteammembers列出小组成成员(6).Nametheprepared填表人(7).EntertheFMEAdate输入FMEA日期(8).Entertherevisiondate输入改版日日期(1)(3)(5)(2)(4)(6)(7)(8)FMEAExample-Step2

FMEA例子-步骤22.Writedowntheprocesssteps.填写流程程步骤AddallvalueaddedprocessstepsfromtheprocessmaptotheFMEAform.把所有增增值流程程步骤填填入FMEA表格Start开始End结束Step2AStep2BStep2CStep1ApplicationofWaxinsidedoorGood?Rework返工YesNoFMEAExample-Step3FMEA例子-步骤3Writedownthefunctionsforeachprocessstep对每个流流程步骤骤，列出出功能Functionsarestatementsofwhattheprocessstepshouldaccomplish.Itcanalsobespecificationsifpossible.功能可以以是规格格（如果果可行）），或者是流流程步骤骤所要完完成工作作的描述述FMEAExample-Step4FMEA例子-步骤44.1.Writedownthepotentialfailuremodeforeachfunction.对每个功功能，列列出潜在在失效模式FMEAKeyPointsAboutStep4.1步骤4.1中的FMEA的重点KeypointsaboutStep4.1:步骤4.1中的重点点:Failuremodesarestatementsofdeficiencyoffunctions.失效模式是对对功能的负面面描述Failuremodesarenotcauses.失效模式不是是原因.Donotdiscussthecauses.Leavethecausestostep4.4不要在此阶段段讨论原因，，在步骤4.4中才讨论原因因4.1.Writedownthepotentialfailuremodeforeachfunction.对每个功能，，列出潜在失失效模式FMEAExample-Step4.2

FMEA例子-步骤4.24.2.Foreachfailuremode,listtheeffectoffailure对每个失效模模式，列出失效效的后果FMEAKeyPointsAboutStep4.2步骤4.2中FMEA的重点KeypointsaboutStep4.2:步骤4.2中的重点Listonly““worstcase”effectsoffailure.只列出最坏的的失效后果Describewhatactuallyhappenswhenthefailuremodeoccurs,ratherthanusinggeneralstatementlike“PartFailed”or“RejectedbyCustomer””抓住失效模式式发生时实际际的情形，避避免概括性描描述，如“部部件不合格””或“客户投投诉”。Themorespecificisthedescriptioninthiscolumn,theeasierwillbethelatersteps(estimatingseverity&listingcauses).通过本节的具具体描述，使使后面的步骤骤（估计严重重性和找出原原因）变的容容易。4.2.Foreachfailuremode,listtheeffectoffailure对每个失效模模式，列出失效效的后果FMEA-Step4.3步骤4.34.3.Writedowntheseverityforeacheffectoffailure对每个失效的的后果，评估严重重性FMEA-Step4.3:AIAG*SeverityGuidelines

FMEA-Step4.3:AIAG*严重性指南Note:AIAGistheAutomotiveIndustryActionGroup,whichcurrentlycompilestheFMEAstandardsfortheNorthAmericanAutoIndustry.备注：AIAG是汽车工业行行动集团缩写写，为目前美美国汽车工业业FMEA编写者FMEAKeyPointsAboutStep4.3步骤4.3FMEA的重点4.3.Writedowntheseverityforeacheffectoffailure对每个失效后后果评估其严重性KeypointsaboutStep4.3:步骤4.3的重点：Someusersadopta1to5system.有些用户采用用1-5分的系统Whateverguidelinesareused…无论使用那种种指南……KeepacopywithyourFMEA.保存FMEA的附件Alwaysmakethehighestnumbermostsevere,thelowestleastsevere.始终让最高严严重性为最高高分，最低严严重性为最最低分FMEAExample-Step4.4

FMEA例子-步骤4.44.4.Writedownthecausesforeachfailuremode对每个失效模模式，列出原原因FMEAKeyPointsAboutStep4.4对每个失效模模式，列出原原因KeypointsaboutStep4.4:步骤4.4的重点UseCauseandEffectDiagramstodoathoroughinvestigationofcausesfortoughfailuremodes.对主要失效模模式用因果图图作一次彻底底的原因分析析Sometimeshypothesistestingcanbeusefulindemonstratingwhetheracauseisstrong.有时假设检验验能有助于证证明一个原因因是否强弱4.4.Writedownthecausesforeachfailuremode.对每个失效模模式，列出原原因Verifytheimportanceofcausestoreducethelistofcauses.通过验证列出出原因的重要要性，防止有有太多的原因因Ifthecausesarealreadyknowntoeveryone,youmaynotcometotherealrootcause.如果你列出那那些是大家都都知道的原因因，你可能仍仍未找到根本本原因FMEAExample-Step4.5

FMEA例子-步骤4.54.5Assessthelikelihoodofoccurrence.评估发生频率率FMEAExample-Step4.5:AIAG*OccurrenceGuidelinesAIAG发生频率指南南Note:AIAGistheAutomotiveIndustryActionGroup,whichcurrentlycompilestheFMEAstandardsfortheNorthAmericanAutoIndustry.备注：AIAG是汽车工业行行动集团的缩缩写，目前北北美汽车工业业FMEA标准编写者FMEAKeyPointsAboutStep4.5步骤4.5FMEA的重点KeypointsaboutStep4.5:步骤4.5的重点Someusersadopta1to5system.有些用户采用用1-5分的系统Whateverguidelinesareused…无论使用那种种指南……KeepacopywithyourFMEA.保存FMEA的附件Alwaysmakethehighestnumbermostfrequent,thelowestleastfrequent.始终让最频繁繁者为最高分分，最不频繁繁者为最低分分4.5Assessthelikelihoodofoccurrenceforeachcauseoffailure.对每个失效原原因评估发生生频率FMEAExample-Step4.6

FMEA例子-步骤4.64.6.Writedownlistthecurrentprocesscontrolsforeachcauseoffailure.对每个失败的的原因，列出现有有流程的控制FMEAKeyPointsAboutStep4.6步骤4.6FMEA的重点KeypointsaboutStep4.6:步骤4.6的重点Writedowntheactualcontrols,notthe““Wannabe”controls.确保列出实际际控制方法,不要列“最理理想”的控制制Bebrutallyhonest,ifthereisnocontrol,justsayit.要坦白诚实，，如果没有控控制要说出来来Normally,thereisnocontrolforthecauseofthefailuremode;butthereisacontroltodetectthefailuremodeitself.一般情况是，，对失效模式式的原因没有有控制，但对对探测失效模模式本身有控控制4.6.Writedownthecurrentprocesscontrolsforeachcauseoffailure.对每个失败的的原因，列出现有有过程的控制ProcessControlExample过程控制案例例Inaninjectionmoldingprocess,injectionpressureofover8000pieze(kilo-pascals)leadstoasmallerdimension.Atalaterstage,thismakesassemblydifficult.有一个模具注注塑工序，注注塑压力超过过8000皮兹（1000帕斯卡）导致致尺寸偏差，，在后面阶段段，装配变的的很困难Aprocesscontrolonthecause(injectionpressure)mightbeasensoronthehydrauliccircuit.对这个原因（（注塑压力））的过程控制制可能是一个个压感应器ProcessControlExample过程控制案例例Aprocesscontrolonthefailuremode(smallerdimension)mightbeaninspectiononthedimension.对这种失效模模式（尺寸偏偏差）的流程程控制可能是是对每个部件件的尺寸进行行检查FMEAExample-Step4.7

FMEA例子-步骤4.74.7.Estimatethedetectionforeachprocesscontrol.对每个过程控控制，估计可可测性FMEAExample-Step4.7:AIAG*DetectionGuidelinesAIAG的可测性指南南Note:AIAGistheAutomotiveIndustryActionGroup,whichcurrentlycompilestheFMEAstandardsfortheNorthAmericanAutoIndustry.备注：AIAG是汽车工业行行动集团的缩缩写，目前北北美汽车工业业FMEA标准编写者FMEAExample-Step5

FMEA例子-步骤55.ComputetheRiskPriorityNumberforeachcauseoffailure.对每个失效原原因，计算风险优先先指数FMEAKeyPointsAboutStep5步骤5FMEA的重点KeypointsaboutStep5:对每个失效原原因，计算风风险优先指数数Anyfailuremodewithaseverityof9or10mustbeidentifiedashighpriorityregardlessoftheRPN.任何严重性为为9-10的失效模式必必须看成优先先级高的风险险指数AddressingthehighestRPNsismoreimportantthansettinganactualtarget(allRPNs<150,forexample).处理最高风险险指数（RPN）比设定目标标（所有RPNs<150为例）更重要要DifferentteamswillobtaindifferentRPNs.不同小组会产产生不同RPNsUsethehighRPNstoidentifycriticalissues(failuremodes,causesoffailures,keyprocessinputs).把高RPNs作为关键问题题（失效模式式，原因模式式，关键过程程输入）5.ComputetheRiskPriorityNumberforeachcauseoffailure.对每个失效原原因，计算风风险优先指数数FMEAExample-Step6

FMEA例子-步骤66.Developrecommendedactionsforhighprioritycausesoffailureand/orfailuremodes,.对高优先级失失效原因或者者失效模式建建议采取行动动FMEAKeyPointsaboutStep6步骤6FMEA的重点KeypointsaboutStep6:步骤6的重点Reducingtheoccurrenceisthemostcosteffectivewaytoreducerisk.降低发发生频频率是是最经经济有有效的的方法法来降降低风风险Actionsrecommendedshouldbelowcostandeffective.所建议议的行行动应应该低低成本本而且且有效效Trytothinkoflowcostactionsthatwillreducetheoccurrence.尝试考考虑低低成本本行动动来降降低发发生频频率Makeuseofideasofallteammembersforimprovement.利用全全体成成员的的智慧慧对过过程进进行改改善6.Developrecommendedactionsforhighprioritycausesoffailureand/orfailuremodes,.对高优优先级级失效效原因因或者者失效效模式式，建建议采采取行行动MoreAboutFMEA-Step6步骤66.Assignresponsibilityandcompletiondeadlineforeachrecommendedaction,.对每个个建议议的行行动，，指定定责任任人和和完成成日期期FMEA-Step7FMEA-步骤77.Implementtheactionandverifyitseffectforeachrecommendedaction.对每个个建议议的行行动，，完成成并记记录结结果FMEAKeyPointsAboutStep7步骤7FMEA的重点点KeypointsaboutStep7:步骤7的重点点Wasitimplemented?YesorNo.落实了了吗？？是或或不是是Howeffectivewasit?Getdata.有效性性如何何？取取得数数据7.Implementtheactionandverifyitseffectforeachrecommendedaction.对每个个建议议的行行动，，完成成并记记录结结果FMEAExample-Step8FMEA例子-步骤88.Re-assesstheseverity,occurrenceanddetectionrankingsandrecalculatetheRPNforeachimplementedaction对每项项完成成的行行动，，重新新估计计严重重性、、发生生频率率和可可测性性并重重新计计算RPN。FMEAKeyPointsAboutStep8步骤8FMEA的重点点KeypointsaboutStep8:步骤8的重点点NeverrecalculateanRPNwithoutimplementinganimprovement!Guessingisnotallowed!在改进进行动动没有有完成成前，，永远远不要重算算RPN，猜测测都不不允许许！Usually,itisdifficulttoreducetheseverityofafailuremode.However,sometimesafailuremodecanbeeliminated.通常，，很难难降低低失效效模式式的严严重性性，不过，，有时时能消消除失失效模模式。。ThemosteffectiveRPNreductionisreducingthelikelihoodofoccurrence.最有有效效降降低低RPN的方方法法是是减减低低可可能能的的发生生频频率率TheleasteffectiveRPNreductionisincreasinginspection(reducingthedetectionranking).Although,Poka-Yokecanreducethedetectionrankingandreducecost!RPN最没没效效的的降降低低方方法法是是增增加加检检查查（（降降低低探探测测性性等等级级）），，虽虽然然如如此此，，POKA-YOKE防错错方方法法能能降降低低探探测测等等级级并并降降低低成成本本8.Re-assesstheseve