失效模式分析 课件

11AnanalyticaltoolforidentifyingPotential

Failuresinaproductorprocesssothatcorrectiveactioncanbetakenbeforethefailurescanreachthecustomer.FMEA是一種識別產品或過程的潛在失效,以便在這些失效影響客戶之前採取措施的分析工具2AnanalyticaltoolforidentifAnFMEAisaStructuredApproachto:FMEA是結構式的方法

Identifyingthewaysinwhichadesignorprocesscanfailtomeetthecriticalcustomerrequirements識別設計或過程可能以何種方式失效而不能滿足客戶重要需求

Estimatingtheriskofspecificcauseswithregardtothesefailures估計產生這些失效的特殊原因的風險

Evaluatingthecurrentcontrolsforpreventingthesefailures評估現有控制手段對這些失效的預防

Prioritizingtheactionsthatmustbetakentoimprovethedesignortheprocess給那些用以改進設計和過程的措施排序3AnFMEAisaStructuredApproaFMEA–History歷史

Firstusedinthe1960’sduringtheApolloMoonMissions.

最早被用於上世紀六十年代的阿波羅登月計劃.

In1974MIL-STD-1629wasdevelopedbytheNavyforusingFMEA’s. 1974年海軍為FMEA的應用制定了MIL-STD-1629.Inthelate1970,adaptedbytheautoindustryinresponsetohigherliabilitycostsandhigherqualitydemandsbycustomers.

在二十世紀七十年代末,為滿足客戶更高的責任成本和質量需求而被用於自動化工業中.4FMEA–History歷史FirstusediFMEAisproactive,notreactive.Don'twaitforthecustomertocomplainifyoucanavoidit! FMEA是預防性

的，不是反應性的。應當儘量避免失效，而不是等著顧客提出申訴！

5FMEAisproactive,notreactiv FMEAreducesthechancethatacustomerwillseeafailure FMEA通過以下措施減少顧客遇到失效的情況:Bydefiningfailureintermsofwhatthecustomerwantsandexpects.

針對顧客的要求和期望確定失效Byshowingwheremeasuresneedtobetakentopreventfailure.

指出爲了防止失效，需要在哪方面採取措施

6 FMEAreducesthechancethatTypesofFMEAs類型Design–usedtoanalyzeproductdesignsbeforetheyarereleasedtoproduction

設計-用於在產品投產前對設計的分析Process–usedtoanalyzemanufacturingprocesses

過程-用於分析製程System–usedtoanalyzesystemsintheearlyconceptanddesignstages

系統–用於分析早期的概念和設計階段的系統7TypesofFMEAs類型Design–usedSummary概要Identifiesknownandpotentialfailuremodes;

識別已知和潛在的失效模式Identifiesthecausesandeffectsofeachfailuremode;

識別每一種失效模式的原因和後果Prioritizesthefailuremodes(usingtheRPN);

利用風險序數（RPN）給失效模式排序Shouldinitiatecorrectiveactionwhereneeded.

必要時提出糾正措施8Summary概要8TimingofanFMEA

FMEA的時機FMEA’sshouldbeinitiatedwhenpreliminarydrawingsofthedesignorprocessareavailable

當初步的設計圖紙和工藝被制定出來時應開始做FMEA

Updatedasidentifiedissuesareresolved

當被發現的問題解決後要更新FMEACanbeusedonexistingproductstoimprovequality

可用於現有的產品以提高質量9TimingofanFMEA

FMEA的時機FMEASystem系統Wiringharness

線束Electronicmodule

電控模塊Assembly

總成SystemFMEAtreatssystemasa“functionalschematic”系統FMEA從“功能關係圖”入手來考慮SFMEA10System系統SFMEA10Ananalyticaltoolusedtoidentifysystem-levelfailuremodes,andidentifycorrectiveactionstobetaken.是一種分析工具用來識別系統失效模式1111ItissimilartoaDesignFMEA,butfocusesonthecircuitschematicinsteadofphysicalfailureofcomponents.

同DFMEA相類似,系統FMEA側重於回路設計而不是元件的物理失效。Takeelectricalsystemsasexamples.以電氣系統為例。12ItissimilartoaDesignFMEAExample: 舉例：Failuremodeatelectricalsystemlevel

電氣系統失效模式OpencircuitatcktA

回路A出現開路Cause:

原因：Terminalunseated

端子脫出Terminalunseated

becomesafailuremodeatthecomponentlevel.

端子脫出是電氣元件的失效模式。13Example: 13RulesofDesignFMEA

設計FMEA規則

Toolfordesignengineersandprojectteamtoimprovethedesigninapreemptivemanner(beforefailureoccur)

是設計工程師和項目小組的工具用來提高設計的前瞻性(在問題發生前)

UsedtoestablishedCriticaltoQualityfeaturesthateffecttheperformanceoftheproduct

用與那些影響產品性能的重要質量特性Usedtoestablish

CriticaltoLifefeaturesthateffectthelifeoftheproduct

用於確定影響產品壽命的重要壽命特性UsedtoestablishCriticaltosafetyfeatures

用於確定重要安全特性14RulesofDesignFMEA

設計FMEA規則PurposeofDesignFMEA

設計FMEA的用途Establishescriticalfeaturesthatmustbecontrolledinmanufacturingtosatisfycustomerrequirements

確定那些必須在生產中進行控制的特性以滿足客戶要求

Identifiesdeficienciesintheproductdesignandassociatedactionitems

找出產品設計中的不足和相應的措施Helpsevaluatetheriskofdesignchanges

幫助評價設計變更的風險15PurposeofDesignFMEA

設計FMEA的PurposeofDesignFMEA

設計FMEA的用途Identifiesprocessdevelopmentneeds

確定開發工藝流程的需求

Dynamicdocument–documentsdesignalternativesandassociatedrisks

動態的文件–記錄可選擇的設計方案和相應的風險Establishesbasesformanufacturingandqualitycontrolplan

建立製造和品質控制計劃的基礎16PurposeofDesignFMEA

設計FMEA的DesignFMEAInputsandOutputs設計FMEA的輸入和輸出

Productdrawings產品圖紙

Productmodels產品模型

Productspecification產品規格

IdentifiedCriticaltoQualityfailures確定的重要質量特性

Actionstopreventthecausesoffailures防止失效原因的措施Actionstodetectfailuremodes發現失效模式的措施HistoryofactionsandResponsibilities措施和責任人的記錄17DesignFMEAInputsandOutputsDesign

设计Components

元件Elements

设计要素DesignFMEAlooksatphysicalfailure

modesofcomponentsanddesignelements设计FMEA着眼于元件及设计要素的物理失效模式DFMEA18DesignDesignFMEAlooksatpRulesofProcessFMEA

過程FMEA規則

Toolforprocessengineersandprojectteamtoimprovethemanufacturingprocessinapreemptivemanner

是工藝工程師和項目小組的工具,用來提高製造工藝的前瞻性

Usedtoprioritizeactionstoensureattentiontocriticalprocessesthateffectcustomers

用與區分先後順序以確保那些影響客戶的重要工藝Usedtodocumentprocessimprovements

用於工藝改進Dynamicdocumentforcontinuousimprovement

持續改進的動態文件19RulesofProcessFMEA

過程FMEA規則PurposeofProcessFMEA

過程FMEA的用途Assistsintheanalysisofnewmanufacturingprocess

幫助分析新的製造工藝

Establishesthebasesformanufacturingprocessinstructionsandcontrolsheets

建立製造工藝文件和控制文件的基礎Identifiesnewmanufacturingprocessneeds

確定新製造工藝的需求

Helpsevaluatetheriskofprocesschanges

幫助評估工藝更改的風險20PurposeofProcessFMEA

過程FMEAProcess

过程Manufacturing

制造Assembling

装配ProcessFMEAlooksatproductfailurescausedbytheprocessfailingtomeetrequirements过程FMEA着眼于因加工過程不符合要求所造成的产品失效PFMEA21ProcessProcessFMEAlooksatFMEATeam小組

Teamapproachisnecessary.

需要團隊的方式ResponsibleforDesignFMEA–DesignEngineer

設計工程師負責設計FMEAResponsibleforProcessFMEA–ManufacturingEngineer

製造工程師負責過程FMEARecommendedrepresentatives:

推薦人選:Design/設計ManufacturingEngineers/製造工程師QualityEngineers/質量工程師Reliability/可靠性Materials/原材料Suppliers/供應商22FMEATeam小組TeamapproachisDefinitionofTerms術語FailureMode–Thewayinwhichaspecificinputrequirementfailsandifnotdetected,correctedorremovedwillcauseanEffecttooccur.

失效模式–一個特殊的輸入要求失敗的方式或者由於未被發覺,糾正或消除而帶來的後果

Effect–Impactoncustomerrequirements

後果–對客戶要求的影響23DefinitionofTerms術語FailureDefinitionofTerms術語Cause–Source(s)ofprocessvariationthatcausestheFailureModetooccur.

原因–造成失效模式發生的過程變差的起源

CurrentControl(proposedcontrols)

當前的控制(建議的控制)Designelementsthat

ensurefunction

確保功能的設計要素Mistakeproofing,automatedcontrols,setupinstructions,gauges

防錯,自動化控制,機器設定指導書,量具Audits,checklists,inspections,PM,etc.. 稽核,檢查表,檢驗,設備維護,等24DefinitionofTerms術語Cause–LinkingFailureModestoEffects失效模式和後果之間的聯繫FailureMode1FailureMode2Effect1FailureMode1Effect2Effect1FailureMode1FailureMode2Effect1NotethattherelationshipbetweentheFailureModeandEffectisnotalways1-to-1請注意失效模式和後果之間的關係不總是一對一Effect225LinkingFailureModestoEffecRiskPriorityNumber風險序數

TheoutputofaFMEAisthe“RiskofPriorityNumber”---RPN

一個FMEA的輸出是“風險序數”---RPN

TheRPNisacalculatednumberbasedoninformationprovidedregarding

RPN是根據下面的資料計算出來的

Thepotentialfailuremodes,

潛在失效模式Theeffects,and

後果Thecurrentorplannedabilitytodetectthefailurebeforeitreachesthecustomer

現有的和已計劃的能力可以在影響客戶前覺察失效26RiskPriorityNumber風險序數TheRiskPriorityNumber風險序數

Itiscalculatedastheproductofthreequantitativerating它是用三個級數計算出來的

RPN=Severity*Occurrence*Detection

風險序數=嚴重度*發生頻度*探測度

TheRPNisnotsacred

RPN不是神聖的

ScalingforSeverity,Occurrence,andDetectionarelocallydeveloped嚴重度,發生頻度,探測度的尺度由自己制定

Othercategoriesmaybeaddedtosuitneed

根據需要可以加上其他類型HighRiskPriorityNumbersaresignificanttothesuccessoftheproductdesign-actionsmustbetakentopreventfailures

高風險序數對產品設計的成功來講很重要-需要採取措施來防止失效27RiskPriorityNumber風險序數ItiDefinitionofRPNTermsRPN術語Severity(ofeffect)–Importancetocustomer,mayinvolvefunction,safety,reliability,orlifeofproduct(1=notsevere,10=verysevere)

嚴重度(後果的)

–對客戶的重要程度,可包括功能,安全,可靠性,產品壽命等方面.(1=不嚴重,10=很嚴重)

Occurrence(ofcause)–FrequencywithwhichagivenCausemayoccur(1=notlikelytooccur,10=verylikelytooccur)

發生頻度(原因的)–一個特定的原因可能發生的頻度(1=不可能發生,10=很可能發生)Detection(CapabilityofcurrentorplannedControls)–Abilitytodetectthecause(1=likelytobedetected,10=notlikelytobedetected)

探測度(現有的或已計劃的控制能力)–覺察原因的能力(1=有可能發覺,10=不可能發覺)28DefinitionofRPNTermsRPN術語SRatingScales評分尺度Rating得分

DegreeofSeverity/嚴重程度

1Customerwillnotnoticetheadverseeffectoritisinsignificant/客戶不會注意到或該不利後果不重要

2Customerwillprobablyexperienceslightannoyance/可能對客戶有輕微的影響3Customerwillexperienceannoyanceduetotheslightdegradationofperformance/由於輕微的性能下降可能給客戶帶來麻煩

4Customerdissatisfactionduetoreducedperformance/由於性能下降使客戶不滿意

5Customerismadeuncomfortableortheirproductivityisreducedbythecontinueddegradationoftheeffect/客戶不滿意或受持續降級的影響使他們的生產力降低

6Warrantyrepairorsignificantmanufacturingorassemblycomplain/保修或者重大的製造或組裝的投訴

7Highdegreeofcustomerdissatisfactionduetocomponentfailurewithoutcompletelossoffunction.Productivityimpactedbyhighscraporreworklevels/零件雖未完全失去功能但引起客戶較大的不滿;由於高報廢,高返工率影響生產力

8Veryhighdegreeofcustomerdissatisfactionduetothelossoffunctionwithoutanegativeimpactonsafetyorgovernmentregulation/由於零件喪失功能而引起客戶極大不滿但尚未違反安全或國家規定

9Customerendangeredduetoadverseeffectonsafesystemperformancewithwarningbeforefailureorviolationofgovernmentalregulations/安全系統的不利影響使得客戶處於危險當中但在失效前有警告或違反國家規定

10Customerendangeredduetoadverseeffectonsafesystemperformancewithoutwarningbeforefailureorviolationofgovernmentalregulations/安全系統的不利影響使得客戶處於危險當中而且失效前沒有警告或違反國家規定

29RatingScales評分尺度Rating得分DegRatingScales評分尺度Rating得分

LikelihoodofOccurrence/發生的可能性1Likelihoodofoccurrenceisremote/發生的可能性極小2Lowfailureratewithsupportdocumentation/有書面證據證明發生的可能性很低3Lowfailureratewithout

supportdocumentation/發生的可能性很低但沒有書面證據證明4Occasionalfailure/偶爾失效5RelativelyModeratefailureratewithsupportingdocumentation/有書面證據證明中等的失效可能性6Moderatefailureratewithout

supportingdocumentation/沒有書面證據證明中等的失效可能性7Relativelyhighfailureratewithsupportingdocumentation/有書面證據證明高度的失效可能性8Relativelyhighfailureratewithout

supportingdocumentation/沒有書面證據證明高度的失效可能性9Failureisalmostcertainbasedonwarrantydataorsignificanttesting/根據保修數據或重要試驗幾乎可以肯定失效會發生10AssureofFailurebasedonwarrantydataorsignificanttesting/根據保修數據或重要試驗可以肯定失效會發生30RatingScales評分尺度Rating得分LikRatingScales評分尺度Rating得分

AbilityofDetect/可探測度

1Surethatthepotentialfailurewillbefoundorpreventedbeforereachingthenextcustomer/確定潛在失效可以在到達下一個客戶前被發現或預防2Almostcertainthatthepotentialfailurewillbefoundorpreventedbeforereachingthenextcustomer/幾乎可以肯定潛在失效可以在到達下一個客戶前被發現或預防3Lowlikelihoodthatthepotentialfailurewillreachthenextcustomer/潛在的失效到達下一個客戶的可能性很低4Controlsmaydetectorpreventthepotentialfailurefromreachingthenextcustomer/控制手段可以防止潛在失效到達下一個客戶5Moderatelikelihoodthatthepotentialfailurewillreachthenextcustomer/潛在的失效到達下一個客戶的可能性中等6Controlsarelikelytodetectorpreventthepotentialfailurefromreachingthenextcustomer/控制手段不太可能防止潛在失效到達下一個客戶7Poorlikelihoodthatthepotentialfailurewillbedetectedorpreventedbeforereachingthenextcustomer/在潛在失效到達下一個客戶前發現或預防的可能性較低8Verypoorlikelihoodthatthepotentialfailurewillbedetectedorpreventedbeforereachingthenextcustomer/在潛在失效到達下一個客戶前發現或預防的可能性非常低9Currentcontrolsprobablywillnotdetectthepotentialfailure/現有控制手段可能探測不到潛在失效10Absolutecertainlythatthecurrentcontrolswillnotdetectthepotentialfailure/完全肯定現有的控制手段無法探測潛在失效31RatingScales評分尺度Rating得分AbiExamplesofOccurrencescale發生率評分的例子ScaleValue分值OccurrencesperWeek週Day日Shift班Hour小時107001003349500712438350501727200291016100145157511445072325412711132ExamplesofOccurrencescaleScExamplesofDetectionscale探測度評分的例子ScaleValue/分值Percentofpotentialfailuresprevented預防潛在失效的比率190%280%370%460%550%640%730%820%910%100%33ExamplesofDetectionscaleScaProcessStep/InputPotentialFailureModePotentialFailureEffectsSEVPotentialCausesOCCCurrentControlsDETRPNActionsRecommended0000000000000000Whatistheinput?輸入是甚麼?Whatcangowrongwiththeinput?輸入會出甚麼錯?WhatistheEffectontheoutput?輸出的後果是甚麼?Whatarethecauses?原因是甚麼?Howwell?程度如何?Howcanthisbefound?怎樣才可以發現?Howoften?頻繁程度Whatcanbedone?可以做甚麼?Howwell?程度如何?34ProcessPotentialFailureModePFMEA–FAILUREMODEEFFECTSANALYSISProduct:ProcessStep/InputPotentialFailureModePotentialFailureEffectsSEVPotentialCausesOCCCurrentControlsDETRPNActionsRecommendedResponsibilityWhatisthesteporinputunderinvestigation?Inwhatwaydoesthekeyinputgowrong?Whatistheimpactonthekeyoutputvariable(customerrequirementorinternalrequirement)Howsevereistheimpactonthecustomer?Whatcausesthekeyoutputtogowrong?Howoftendoescauseoffailuremodehappen?Whataretheexistingcontrolsandprocedures(inspectionandtesting)thatpreventeitherthecauseorthefailuremode?IncludeshopoperatingprocedurenumberHowwellcanthefailuremodeofcausebedetected?RPN=SEV*OCC*DETWhataretheactionsforreducingtheoccurrenceofthecauseorimprovingdetection?ShouldhaveactionsonallhighRPNnumbers.Whoisresponsibleforimplementingtherecommendedactions?000035FMEA–FAILUREMODEEFFECTSANFMEAModel模式Prevention/預防Prevention/預防Prevention/預防Cause/原因Effect/後果FailureMode/失效模式Controls/控制Materialorprocessinput/原料或過程輸入ProcessStep/工序Externalcustomerordownstreamprocessstep/外部客戶或下一工序36FMEAModel模式Prevention/預防PrevGeneralStepsintheDFMEA/一般步驟

SelectdesignFMEAteam

組建設計FMEA小組Listcustomerrequirements

列出客戶的要求

Foreachcustomerrequirementlistthekeydesignelementsthatsatisfythecustomerrequirements

針對客戶的每一個要求列出滿足該要求的關鍵設計要素Foreachkeydesignelementlistwaysthatthedesignelementcouldvary,PotentialFailureModes

列出每一個關鍵設計要素的變化,潛在的失效模式ListEffectsofeachFailuremodeonthecustomerrequirement

列出每個失效模式的對客戶要求的影響ListCausesforeachfailureMode

列出失效模式的原因37GeneralStepsintheDFMEA/一般步GeneralStepsintheDFMEA/一般步驟

Listcurrentcontrolsforeachcause

列出每個原因的現有控制手段

AssignSeverity,Occurrence,andDetectionratingstoeachcause

給每個原因的嚴重度,頻度,可探測度評分CalculateRPNs

計算風險序數RecommendactionstoreducehighRPNs

提出降低風險序數的措施Takeappropriateaction

採取適當的措施

RecalculateRPNs

重新計算風險序數38GeneralStepsintheDFMEA/一般步Aschematicrepresentation,with

一種圖示法,其中

Components(orfeatures)shownasblocks,

用方塊表示各元件(或特性)Interactionsbetweencomponentsshownaslines,

用直線表示各元件之間的關係Attheappropriatelevelofdetail

詳細到恰當的程度

DevelopaFunctionalBlockDiagramofTheProduct

繪制產品功能結構圖39Aschematicrepresentation,wiComponent元件Component元件Component元件Component元件Component元件Component元件BlockDiagram結構圖Examples例如40ComponentComponentComponentComDon'tforgetauxiliaryfunctionsaswellaprimaryfunctions

主要功能和輔助功能都要考慮Often,componentsworktogethertoperformafunction

經常是幾個零件共同實現一個功能Hint:UsetheBlockDiagram!

提示:利用結構圖ListTheFunction(s)ofEachComponent

列出每個要素的功能41Don'tforgetauxiliaryfunctioAdefect,flaw,orotherunsatisfactoryconditionintheproductthatiscausedbyadesignweakness

由於設計缺陷造成的產品缺陷,瑕疵或其它令人不滿意的情況TypicalFailureModes:

典型的失效模式 -Breaks -Cracks

破碎

裂紋 -Corrodes -Sticks

腐蝕

粘結

-Deforms/melts

變形/熔化42Adefect,flaw,orotherunsatStartwiththeprevioustwosteps:

從前両個步驟入手:

Functions

功能Qualityrequirements

質量要求43StartwiththeprevioustwostInyourowndescriptivewords,writedownthefollowingscenarios，用自己的語言描述下列假設：

Failure=Nofunction，失效=無功能Failure=Notenoughfunction，失效=功能不足Failure=Toomuchfunction，失效=功能過強Similarly,同樣：Failure=Noqualityrequirement

失效=未達到質量要求44Inyourowndescriptivewords,Aneffectcanbe，後果可能是：Completelossoffunction，功能完全喪失Degradationofperformanceorquality

性能或質量下降Manyfailuremodeshavemorethanoneeffect!

許多失效模式不止有一個後果！Effectsoffailureoftenshowupasachainofevents,fromimmediateeffecttotheultimateeffectonthecustomer

失效模式的後果經常表現為對客戶的一連串的影響,包括直接的後果和最終的後果45Aneffectcanbe，後果可能是：45DeterminePotentialCause(s)ofEachFailureMode

確定每種失效模式的潛在原因Acauseoffailureisadesignweaknessthatleadstothefailuremode

造成失效的原因是由於設計缺陷引起Inherentinthewaytheproductwasdesigned

是產品設計所固有的Relativetotheusageoftheproduct

與產品的使用方法有關Manyfailuremodeshavemultiplecauses!

許多失效模式有多個起因！46DeterminePotentialCause(s)oIfthedesignas-isweretogointoproduction.如果依據現有設計進行生產的話Usehistoricaldata，利用歷史資料Takeimprovementsintoaccount，參考已有的改進Considerthelifespanoftheproduct，考慮產品的壽命Usereliabilitymodelsandcomparisonwithsimilarproducts，利用可靠性模型並與類似產品比較AssessTheLikelihoodofOccurrenceofEachCause

評估每種原因發生的可能性47Ifthedesignas-isweretogoTherearethreetypesofdesigncontrols:

設計控制有三種類型：(1)Thosethatpreventthecauseoffailure;

預防產生失效的原因；(2)Thosethatdetectthecause(s)offailure;

覺察產生失效的原因；(3)Thosethatdetectthefailuremode(s)檢測失效模式48TherearethreetypesofdesigDetectionRating(D):探測度評分 9-10 Remotechanceofdetectingfailure

察明失效的可能性極小 7-8 Verylowchance，可能性很小 5-6 Lowtomoderatechance，可能性不大 2-4 Goodchance，可能性較大1 Willalmostcertainlydetectfailure (Ifitpassesthis,itwillnotfail)

失效幾乎都可以被査到(如果通過這樣的 檢查就不會有失效)49DetectionRating(D):探測度評分49Toreduceseverity--designchangetocontroltheeffect

降低嚴重度–通過設計更改來控制後果Toreduceoccurrence--designchangetocontrolthecause

減少發生頻度--通過設計更改來控制原因Toimprovedetection--improvedtestingorsimulationmethods

增強探測度–改進測試和模擬方法Special

AttentionifSeverity=9or10

當嚴重度為9或10時要特別注意50Toreduceseverity--designcGeneralStepsinthePFMEA/一般步驟

SelectprocessFMEAteam

組建過程FMEA小組

DevelopaProcessMapandidentifyallprocesssteps

做一個流程圖確定過程的所有步驟ListalltheKeyProcessOutputstosatisfyinternalandexternalcustomerrequirement

列出所有的滿足內部和外部客戶要求的關鍵過程輸出Foreachprocessstep,listKeyProcessInputVariables

列出每一步的關鍵過程輸入變量FortheProcessDefineC&EmatrixrelatingKeyOutputstoKeyProcessInputVariable

用因果圖分析關鍵過程輸入和關鍵輸出的聯繫

RanktheKPIVsaccordingtoimportance

根據重要程度給關鍵過程輸入變量分級

StarttheprocessFMEA

開始做過程FMEA51GeneralStepsinthePFMEA/一般步GeneralStepsinthePFMEA/一般步驟

Foreachprocessinput,listwaysthatitcanvary(failureModes)andidentifyassociatedeffects

對每一個過程的輸入,列出其可能的變化和相應的後果

ListallCausesforeachFailureMode

列出失效模式的所有原因ListthecurrentControlsforeachcause

列出每個原因的現有控制手段AssignSeverity,Occurrence,andDetectionratingstoeachcause

給每個原因的嚴重度,頻度,可探測度評分CalculatetheRPNforeachpotentialFailureModescenario

計算每個潛在失效模式的風險序數

DeterminerecommendedactionstoreduceHighRPNs

提出降低風險序數的措施

Takeappropriateactions

採取適當的措施RecalculateRPNs

重新計算風險序數52GeneralStepsinthePFMEA/一般步UsetheProcessFlowDiagramformat

適用流程圖的格式Identifiesfabricate,move,storeandinspectoperations

識別四種作業類型,製造,移動,儲存,檢驗IdentifiesKeyCharacteristics

識別關鍵特性Afunctioniswhattheoperationdoes

功能系指該操作所起的作用

Statethefunctionas/说明功能为：Verb+Object+Qualifier

动词+宾语+修饰词

Moldpart/成型零件

Crimpterminalontocable/電線上壓接端子

Formbendinpart/零件彎曲成形53UsetheProcessFlowDiagramfAcustomerwantordesire

顧客的希望或要求

Couldseriouslyaffectcustomerperception

有可能嚴重影響顧客的看法

Couldleadtoacustomercomplaint 有可能導致顧客投訴

Adefect,flaw,orotherunsatisfactoryconditionintheproduct

thatoccurswhentheprocessfailstomeettheprocessrequirements

由於過程未達到要求而導致的産品缺陷、瑕疵等不良狀態

Failuremodesshouldbewrittenintermsoftheconditionoftheproduct

失效模式體現在産品上

54Acustomerwantordesire54

TypicalFailureModes/幾種典型失效模式

Diameteroutofspec./直径超差Missingseal/漏裝密封墊Cutstrands/切破線皮Miss-orientedpart/部件方向錯Insufficientsolder/焊劑不足Toomuchsolder/焊劑過量NFO,Flash/未充滿,飛邊Theramificationsoffailure/後果是失效模式的衍生事件

Theeffectcanbeon/可能影響Theultimatecustomer/最終用戶Orintermediatecustomer(OEM,etc.)/中間用戶Agovernmentregulation/政府法規Thenextprocessstep/下工序55TypicalFailureModes/幾種典型失效

Customercomplaintsareausefulsourceofinformation顧客抱怨是非常有用的資訊來源

Aneffectcanbe/後果可能是

Completelossoffunction/功能完全喪失Degradationofperformanceorquality/質量或性能下降Damageofprocessequipment/設備受損

Injurytoanoperator/員工受傷Shut-downofanassemblyline/停線Effectsoffailureoftenshowupasachainofevents,fromimmediateeffecttotheultimateeffectonthecustomer/失效的後果

通常表現爲從對顧客的直接影響到最終影響等一系列連鎖反應

ItisrecommendedthatthesechainsbedevelopedforeachfailuremodeandrecordedontheFMEAform/建議針對每一種失效模式找出這些連鎖反應，並記錄在FMEA表上

56CustomercomplaintsareauseAcauseoffailureishowthefailurecanoccurintheprocess失效原因就是過程爲何會失效

Shouldbewrittenintermsofsomethingintheprocessthatcanbecorrectedandcontrolled應表述爲可糾正或可控制的因素

Considerhumanerror,wear-outoftools,ambientconditions,andinteractionsoffactors如人的過失，工裝磨損、環境條件以及因素間的相互作用

57AcauseoffailureishowtheEffectsontheprocess/對過程的影響9-10

Mayendangermachineoroperator/ 可能導致設備或人員受損

6-8 Scrap/報廢4-5

Sortandrework/篩選和返工2-3

Reworkon-line/在線返工1

Noeffect/無影響ConsiderAlsotheEffectsontheCustomer还要考虑对顾客的影响58Effectsontheprocess/對過程的影響

Usehistoricaldata(asabaseline)/利用歷史資料

Takeimprovementsintoaccount

考慮改進9-10 Failurealmostinevitable/失效幾乎不可避免

7-8

Similarprocessesthathaveoftenfailedinthepast

以前類似過程常常失效

4-6

Similarprocessesthathaveoccasionalfailures

類似過程偶爾失效

1-3

Similarprocessesthathaveexperiencedisolated failures/類似過程僅有過個別失效

59Usehistoricaldata(asabasCause-and-EffectChain因果鏈ToolIsWorn夾具磨損ToolNotReplaced夾具未更換LackofMaintenanceProcedure/沒有保養程序ClampCracksatBend夾子在彎曲處裂紋BundleFallsOut線束散開RattlingNoise卡嗒聲噪音CAUSEchain原因鏈EFFECTchain後果鏈RadiusOutOfSpec半徑超差60Cause-and-EffectChainToolIsCrossedWire交叉的電線NoFunction沒有功能CausesTree/原因樹EffectsTree/後果樹FireinPlant工廠起火OperatorInjury員工受傷DamagedEquip設備損壞MustRepairVehicle必需維修車輛PoorInstruction指導書不足NotTrained未培訓OperatorError操作員錯誤BoardError電路板錯誤OperatorTired操作人員疲勞CrossedWire交叉的電線61CrossedNoCausesTree/原因樹EffecProcesscontrolscatchthedefectbeforetheproductreachesthecustomer/程序控制當在産品到達顧客前發現缺陷!

Therearethreetypesofprocesscontrols

程序控制有三種類型

:(1)Preventthecauseoffailure,orreducetherateofoccurrence防止原因出現或降低其出現的可能性

(2)Detectthecause(s)offailureandleadtocorrectiveactions查明失效的原因並找出糾正措施

(3)Detectthefailuremode(s)/檢測失效模式

AssignCurrentlyusedprocesscontrolstofailuremodesandcauses

針對失效模式或原因列出現行的程序控制手段62Processcontrolscatchthedef

Detectionisanassessmentoftheprobabilitythat探測度爲下列事件發生的概率

Atype2controlcandetectthecauseandleadtocorrectiveaction

第2類控制能夠發現原因並找到糾正措施

Atype3controlcandetectafailure

第3類控制能夠在不良品到達顧客前發現缺陷

...beforetheproductreachesthecustomer!

Detectioncanalsoassesshoweffectivelyatype1controlcanpreventfailure

第1類控制能夠預防失效的有效程度

63DetectionisanassessmentofAimforPREVENTIONratherthandetection

目的是預防而不是探測BeginwiththehighestRPNitem

從RPN高的專案開始

Don’tsetanaprior“cut-off”value(i.e.priortobeginningtheFMEA)

勿預先設定“分數線”(例如在開始做FMEA前)GiveseriousattentiontoitemswithSeverity=9or10

嚴重度＝9或10時應特別注意

64AimforPREVENTIONratherthanWhatcorrectiveaction,ifany,shouldbetakentoreduce應採取哪些措施以降低

Severity(probablyneedadesignchange)

嚴重度（可能需修改産品設計）

Likelihoodofoccurrence發生的可能性Detectionrating/可探測度

Youdon'trecommendcorrectiveaction?LowRPN?

你不建議採取糾正措施嗎？RPN較低？

Don'tleavethespaceontheformblank.Write"None"

不要在表上留下空格不填。應填寫“無”

65Whatcorrectiveaction,ifanyRecordedontheform/記入表內以便

totrackprogress/追蹤進展

todocument“duecare”/說明“應有的注意”Completiondateandabriefdescription

完成日期和簡要說明

RecalculatetheRPN/重新計算RPNVerifyimprovementwithsupportingdata!!!

利用支持的數據來確認改進

Consequences/結果Mayreprioritizethefailures

有可能對失效重新排序

Mayleadtofurthercorrectiveaction

有可能需要進一步改進

66Recordedontheform/記入表內以便 6FMEAmustneverbedonebyanindividual,because 絕不能由個人單獨做FMEA，因爲

：

Individualeffortsproducebiasedresults, 由個人進行會使結果出現偏差

Anyactionswillrequirebuy-infromvariousgroups 進行任何活動，都需要從不同的組織取得資訊67FMEAmustneverbedonebyan謝謝!68謝謝!68691AnanalyticaltoolforidentifyingPotential

Failuresinaproductorprocesssothatcorrectiveactioncanbetakenbeforethefailurescanreachthecustomer.FMEA是一種識別產品或過程的潛在失效,以便在這些失效影響客戶之前採取措施的分析工具70AnanalyticaltoolforidentifAnFMEAisaStructuredApproachto:FMEA是結構式的方法

Identifyingthewaysinwhichadesignorprocesscanfailtomeetthecriticalcustomerrequirements識別設計或過程可能以何種方式失效而不能滿足客戶重要需求

Estimatingtheriskofspecificcauseswithregardtothesefailures估計產生這些失效的特殊原因的風險

Evaluatingthecurrentcontrolsforpreventingthesefailures評估現有控制手段對這些失效的預防

Prioritizingtheactionsthatmustbetakentoimprovethedesignortheprocess給那些用以改進設計和過程的措施排序71AnFMEAisaStructuredApproaFMEA–History歷史

First