DFMEA设计潜在失效分析培训课件

2024/5/7DesignFailureModeand

EffectsAnalysis

设计失效模式及后果分析(DFMEA)

DFMEA

DFMEA2024/5/7APQP

CustomerNeedsDesignChar.Design

FMEAProcessChar.Characteristics

MatrixProcessFlowchartsInternalNeeds&ConstraintsProcess

FMEAControl

PlanProcess

CapabilityMeas.Sys.AnalysisSPCProcess

InstructionsDFM2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/7DesignFMEA，(forComponents)

设计FMEA(元件级)ananalyticaltoolusedbyaproductdesignteamtoidentifypotentialproductfailuresthatareinherenttothedesign,andidentifycorrectiveactionstobetaken

是产品设计小组采用的一种分析方法，用于识别设计中固有的潜在产品失效模式，并确定所应采取的纠正措施。2024/5/7DesignFMEA

设计FMEAformalprocess

正式程序customerfocused

着眼于顾客usesengineeringjudgment,andharddatawhereitisavailable

利用工程经验判断和可靠的数据2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/7WhendowedoaDFMEA?

何时进行DFMFA？Whilethereisstilltimetobringaboutchangesinthedesign!

当还有时间修改设计时！ADFMEAdoneafterthefactisjustanexercise

事后进行DFMEA，仅是练习而已2024/5/7DFMEAisanoutputofthe"ProductDesignandDevelopment"phaseofAPQP

DFMEA是APQP中“产品设计和开发”阶段的产物WhendowedoaDFMEA?

何时进行DFMFA？2024/5/7Initiated

after

an

analysis

ofcustomerrequirementsandcompletionofaninitialconcept

在分析了顾客要求和形成初始概念之后进行priortoaPFMEA,ofteninconjunctionwith

在PFMEA之前，通常与DFM一道进行andshouldbeanaturalpartofconceptdevelopment

应成为概念发展为详细设计的一个必要组成部分itisalivingdocument

是动态文件WhendowedoaDFMEA?

何时进行DFMFA？2024/5/7DoaDFMEA(oratleastreviewtheoldone)if:以下情况需进行DFMEA(或至少评审过去的DFMEA)：thedesignisnew

是新的设计anolddesignchanges

在原设计基础上修改theapplicationorenvironmentchanges

应用条件或环境发生变化customerrequirementsordesireschange

顾客要求或希望发生变化WhendowedoaDFMEA?

何时进行DFMFA？2024/5/7DoaDFMEA(oratleastreviewtheoldone)if:以下情况需进行DFMEA(或至少评审过去的DFMEA)：thecompetitive,business,orlegalenvironmentchanges

竞争环境、业务环境或法律环境发生变化youaredesignresponsibleandPPAPconditionsapply

有设计责任且需提交PPAPactualfailuresoccur

发生实际失效WhendowedoaDFMEA?

何时进行DFMFA？2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/7WhoperformsaDFMEA?

由谁进行DFMEA？Across-functionalteamofrepresentativesfromareasthataffectthedesign

由来自对设计具有影响的各方代表组成的跨部门小组进行Suppliersmightalsobeinvolved

供应商也可以参加Don'tforgetaboutthecustomer

切不要忘记顾客Theleadershouldbethedesign-responsibleengineer

小组组长应是设计责任工程师2024/5/7Cross-FunctionalTeam

跨部门小组5-9peoplefrom 5-9人，由从事如下工作的人员组成

systemsengineering，系统工程componentengineering，零部件设计testlabs，试验室materialsengineering，材料工程processengineering，过程过程toolengineering，工具设计manufacturing，制造quality，质量管理2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/7HowdowedoaDFMEA?

ASummary

怎样进行DFMEA？提要Assemblethecross-functionalDFMEAteam

组建跨部门DFMEA小组Listthefailuremodes,theireffects,andtheircauses

列出失效模式，后果以及原因2024/5/7Assess， 评估 theseverityoftheeffect(S)

后果的严重程度thelikelihoodofthecauses(O)

原因出现的可能性 andtheabilityofdesigncontrolstodetectfailuremodesand/ortheircauses(D)

设计控制探测失效模式和/或原因的能力HowdowedoaDFMEA?

ASummary

怎样进行DFMEA？提要2024/5/7Calculatetheriskprioritynumber(RPN)toprioritizecorrectiveactions

计算风险顺序数(RPN)以确定应优先采取的纠正措施Plancorrectiveactions

制订纠正措施Performcorrectiveactionstoimprovetheproduct

采取纠正措施以提高产品质量RecalculateRPN

重新估算RPNHowdowedoaDFMEA?

ASummary

怎样进行DFMEA？提要2024/5/7HowdowedoaDFMEA?

ASuggestion

怎样进行DFMEA？建议Doyourworkonscratchpaperfirst;astheteamreachesconsensus,recordtheinformationontheFMEAform

先在一张草稿纸上进行分析；当小组达成一致意见后，再将有关信息填在FMEA表上usefishboneandtreediagramsliberally

充分利用鱼刺图和树形图tryingtousetheFMEAformasaworksheetleadstoconfusionandmessed-upFMEAs

若将FMEA表当做工作单使用，就会造成混乱，使FMEA一塌糊涂2024/5/7DesignFMEA

设计FMEA何谓DFMEA何时作DFMEA何人作DFMEA如何作DFMEA16步工作步骤2024/5/71.Assembleateamand

planyouractivities

成立小组并制订计划DFMEAmustneverbedonebyanindividual,because

绝不能由个人单独进行DFMEA，因为：individualeffortsproducebiasedresults,

由个人进行会使结果出现偏差anyactionswillrequirebuy-infromvariousgroups

进行任何活动，都需要从不同的组织取得信息2024/5/7Oneperson(e.g.theleader)shouldbeassignedtomaintainingtheFMEAform

应指定一个人(如组长)保管FMEA表格BesuretowritethenamesandfunctionsoftheteammembersontheFMEAform

应将小组成员的姓名和职责填入FMEA表格1.Assembleateamand

planyouractivities

成立小组并制订计划2024/5/72.Developafunctionalblock

diagramoftheproduct

绘制产品功能结构图Aschematicrepresentation,with

一种图示表示法，其中包括：components(orfeatures)shownasblocks,

用块表示的各种元件(或特性)interactionsbetweencomponentsshownaslines,

用直线表示的各元件之间的相互关系attheappropriatelevelofdetail

详细到恰当的程度2024/5/7Blockdiagram

结构图component

元件component

元件component

元件component

元件component

元件component

元件2.Developafunctionalblock

diagramoftheproduct

绘制产品功能结构图2024/5/73.Listthefunction(s)of

eachcomponent

列出每个要素的功能Afunctioniswhatthecomponentdoes

功能系指该要素所起的作用Statethefunctionas，说明功能为：Verb+Object+Qualifier动词+宾语+修饰词

insulatescore，使线芯绝缘

assuresterminalpositioninconnector

保证端子在插接件内位置正确

protectstangfromsmashing,防止管脚被压碎examples例如2024/5/7Don'tforgetauxiliaryfunctionsaswellaprimaryfunctions

基本功能和辅助功能都要考虑Often,componentsworktogethertoperformafunction

通常是几个元件共同行使某一功能Hint:UsetheBlockDiagram!

提示：利用结构图！3.Listthefunction(s)of

eachcomponent

列出每个要素的功能2024/5/74.Listthequality

requirements

列出质量要求acustomerwantordesire

顾客的希望或要求couldseriouslyaffectcustomerperception

有可能严重影响顾客的看法couldleadtoacustomercomplaint

有可能导致顾客投诉Hint:UseQFD

提示：使用质量功能展开2024/5/75.Listthepotential

failuremodes

列出潜在的失效模式adefect,flaw,orotherunsatisfactoryconditionintheproductthatiscausedbyadesignweakness

设计缺陷造成的产品缺陷、瑕疵或其它令人不满意的情况物理状况2024/5/75.FailureModes

失效模式TypicalFailureModes:

典型的失效模式

-breaks -cracks

破碎 裂纹

-corrodes -sticks

腐蚀 粘结

-deforms/melts

变形/熔化2024/5/75.Hint

提示Startwiththeprevioustwosteps:

从前两个步骤做起：functions

功能qualityrequirements

质量要求2024/5/7Inyourowndescriptivewords,writedownthefollowingscenarios，描述下列情况：

failure=nofunction，失效=无功能failure=notenoughfunction，失效=功能不足failure=toomuchfunction，失效=功能过强similarly,同样：failure=noqualityrequirement

失效=未达到质量要求5.Hint

提示2024/5/76.Derivethepotential

effectsofeachfailure

各种失效模式的潜在后果Theramificationsoffailure，失效的结果Effectscanbeon，有可能影响到anultimateorintermediatecustomer，最终或中间顾客agovernmentregulation，政府法规somepartofthesystemhierarchy，系统结构的某一部分Customercomplaintsareausefulsourceofinformation

顾客的投诉是有用的信息来源2024/5/76.EffectsofFailure

失效的后果Aneffectcanbe，后果可能是：completelossoffunction，功能完全丧失degradationofperformanceorquality

性能或质量下降Manyfailuremodeshavemorethanoneeffect!

许多失效模式有不止一种后果！Hint:beginwiththe“Nofunction”scenariosthatyoudevelopedearlier

提示：始于你在上面所提到的“无功能”情况2024/5/7Effectsoffailureoftenshowupasachainofevents,fromimmediateeffecttotheultimateeffectonthecustomer，失效的后果通常表现为从对顾客的直接影响到最终影响等一系列连锁反应ItisrecommendedthatthesechainsbedevelopedforeachfailuremodeandrecordedontheFMEAform

建议针对每一种失效模式找出这些连锁反应，并记录在FMEA表上useatreediagram

运用树形图6.EffectsofFailure

失效的后果2024/5/7Iftheeffectisonsafetyorcompliancewithgovernmentregulation,thisshouldbeexplicitlystatedassuch

如果影响了安全或违反了政府法规，就应如实讲清。6.EffectsofFailure

失效的后果2024/5/77.Assesstheseverity

ofeacheffect

评估每种后果的严重度TheAIAGseveritycriteriaweredevelopedforvehicle-levelfailures.Itishelpfultotranslatethistableintothelanguageofyourspecificproduct. AIAG严重度评估标准是针对整车发生的故障制订的。可结合产品制订自己的评分表。2024/5/7RankSeverity(S)EffectCriteria:SeverityofEffect10Hazardous-

withoutwarningVeryhighseverityrankingwhenapotentialfailuremodeaffectssafevehicleoperationand/orinvolvesnoncompliancewithgovernmentregulationwithoutwarning.9Hazardous-

withwarningVeryhighseverityrankingwhenapotentialfailuremodeaffectssafevehicleoperationand/orinvolvesnoncompliancewithgovernmentregulationwithwarning.8VeryHighVehicle/iteminoperable(lossofprimaryfunction).7HighVehicle/itemoperablebutatareducedlevelofperformance.Customerverydissatisfied.6ModerateVehicle/itemoperablebutComfort/Convenienceitem(s)inoperable.Customerdissatisfied.5LowVehicle/itemoperablebutComfort/Convenienceitem(s)operableatreducedlevelofperformance.4VeryLowFit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedbymostcustomers(greaterthan75%).3MinorFit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedby50%ofcustomers.2VeryMinorFit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedbydiscriminatingcustomers(lessthan25%).1NoneNodiscernibleeffect.严重度评分表2024/5/78.Determinepotentialcause(s)

ofeachfailuremode

确定每种失效模式的潜在原因Acauseoffailureisadesignweaknessthatleadstothefailuremode

形成失效模式的设计缺陷是造成失败的原因inherentinthewaytheproductwasdesigned

是产品设计所固有的relativetotheusageoftheproduct

与产品的使用有关Manyfailuremodeshavemultiplecauses!

许多失效模式是多种原因造成的！2024/5/78.Cause(s)ofFailure

失效原因Documenttheconditionsthatcanleadtofailure

说明导致失效的情况e.g.stressexceedsstrength，如应力超过强度Consider"foreseeablemisuse"oftheproduct

考虑“可预见的产品误用”情况e.g.replacinga10Afusewitha20Afuse

如用一根20A保险丝代替10A保险丝Also,considerthelifespanoftheproduct

此外，还应考虑产品的使用寿命2024/5/7Causesoffailureoftenshowupasachainofevents,fromimmediatecausetorootcause

失效通常是由一连串的原因造成的，从直接原因到根本原因ItisrecommendedthatthesechainsbedevelopedforeachfailuremodeandrecordedontheFMEAform

建议针对每一种失效模式，找出原因链，记入FMEA表useatreeorfishbonediagramtodevelop

可利用树形图或鱼刺图8.Cause(s)ofFailure

失效原因2024/5/7Causeandeffectdiagram

原因和结果图形failuremode

失效模式cause

原因cause

原因8.Cause(s)ofFailure

失效原因2024/5/7RankOccurence(O)ProbabilityLikelyFailureRates*10VeryHigh:

PersistentFailures>=100per

thousandpieces9VeryHigh:

PersistentFailures50perthousandpieces8High:

FrequentFailures20perthousandpieces7High:

FrequentFailures10perthousandpieces6Moderate:

OccasionalFailures5perthousandpieces5Moderate:

OccasionalFailures2perthousandpieces4Moderate:

OccasionalFailures1perthousandpieces3Low:Relatively

FewFailures0.5perthousandpieces2Low:Relatively

FewFailures0.1perthousandpieces1Remote:Failure

isUnlikely<=0.010perthousandpieces频度评分表2024/5/79.Assessthelikelihoodof

occurrenceofeachcause

评估每种失效原因产生的可能性ifthedesignas-isweretogointoproduction.如果依据设计现有进行生产的话

Usehistoricaldata，利用历史资料Takeimprovementsintoaccount，记及已做的改进Considerthelifespanoftheproduct，考虑产品使用寿命Usereliabilitymodelsandcomparisonwithsimilarproducts，利用可靠性模型，与类似的产品进行比较2024/5/710.ListtheCurrent

DesignControls

列出现有设计控制DesignControl:anytechniqueforassuringdesignadequacy

设计控制：能够确保设计充分性的任何技术DFMAnalysis，DFM分析Durability/ValidationTesting

耐久性/验证试验FiniteElementAnalysis，有限元分析Simulation，仿真模拟2024/5/710.DesignControls

设计控制PurposeinFMEA，FMEA的目的在于Toverifythefailuremodes&theircauses

确认失效模式及其原因Cantheproductreallyfailthisway?

产品确实会这样失效吗？Cantheproductfailinanyotherway?

产品还有其它失效模式吗？Havethetruecausesoffailurebeenidentified?

是否已找到失效的真正原因？Topreventfailurefromoccurring

防止发生失效2024/5/7Afailuremodeislikeadiseaseandadesigncontrolislikeadiagnostictestusedbyadoctor

失效模式如同疾病，设计控制则象医生采取的诊断方法nofalsenegatives，无虚假否定nofalsepositives，无虚假肯定(doctorprefersprevention) (医生喜欢采取预防方法)10.DesignControls

设计控制2024/5/7Therearethreetypesofdesigncontrols:

设计控制有三种类型：(1)thosethatpreventthecauseoffailure;

消除失效产生的原因；(2)thosethatdetectthecause(s)offailure;

查明失效的原因；(3)thosethatdetectthefailuremode(s)

检测失效模式10.DesignControls

设计控制2024/5/7OntheFMEAform,assigndesigncontrolsthatareusedonthesameorsimilardesigns

在FMEA表上指出用于相同或类似设计的设计控制手段Designcontrolsareassignedtofailuremodesorcauses

设计控制方法用于控制失效模式或原因CanbeofanyType:1,2,or3,oranycombination

可以采取前述的任何类型：1，2或3，或任意组合Ifnone,write"None"

如果没有，可写“无”10.DesignControls

设计控制2024/5/711.Detectingfailure

探测度DetectionRating(D):探测度评分(D) 9-10 remotechanceofdetectingfailure

查明失效的可能性极小

7-8 verylowchance，可能性很小

5-6 lowtomoderatechance，可能性不大

2-4 goodchance，可能性较大

1 willalmostcertainlydetectfailure (ifitpassesthis,itwillnotfail)

几乎都可以查到(如能通过这项检测，就不会失效)2024/5/7RankDetection(D)DetectionCriteria:LikelihoodofDetection

byDesignControl10Almost

ImpossibleDesignControlwillnotand/orcannotdetectapotentialcause/mechanismandsubsequentfailuremode;orthereisnoDesignControl.9Very

RemoteVeryremotechancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.8RemoteRemotechancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.7VeryLowVerylowchancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.6LowLowchancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.5ModerateModeratechancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.4Moderately

HighModeratelyhighchancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.3HighHighchancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.2VeryHighVeryhighchancetheDesignControlwilldetectapotentialcause/mechanismandsubsequentfailuremode.1Almost

CertainDesignControlwillalmostcertainlydetectapotentialcause/mechanismandsubsequentfailuremode探测度评分表2024/5/712.CalculatetheRisk

PriorityNumber(RPN)

计算风险顺序数(RPN)RPN = SxOxD = SeverityofEffect xOccurrenceRating xDetectionRating = 后果的严重度

x原因