過程失效模式分析

ProcessFailureMode

andEffectsAnalysis

過程失效模式及效果分析(PFMEA)1HISTORY-FMEAFMEA的歷史TheFMEAprocesswasoriginallydevelopedbytheUSmilitaryin1949toclassifyfailures“accordingtotheirimpactonmissionsuccessandpersonnel/equipmentsafety〞.失效模式及效果分析最初是由美國軍方于1949年開發(fā)出來用以根據(jù)失效對成功完成使命以及人員和設(shè)備平安的影響對失效進行分級。FMEAhassincebeenusedonthe1960sApollospacemissions.在二十世紀六十年代失效模式及效果分析被用于阿波羅太空方案。Inthe1980sitwasusedbyFordtoreducerisksafteronemodelofcar,thePinto,sufferedafaultinseveralvehiclescausingthefueltanktoruptureandittosubsequentlyburstintoflamesaftercrashes.二十世紀八十年代，在經(jīng)歷了一款名為Pinto的汽車由于在碰撞后一個故障導致幾臺汽車的油箱發(fā)生破裂，進而導致爆炸燃燒的事故后，福特汽車公司把這種方法用于減小風險。2Objectofthecourse課程目的IntroducestheconceptofFMEA介紹潛在失效模式及效果分析的概念ProvidemethodofdevelopingandimplementingFMEA提供開發(fā)和實施FMEA的方法DiscusstheevaluationcriteriaofFMEA討論FMEA的評估準那么Casestudy案例研究3FMEADescriptionFMEA描述Failuremodesandeffectsanalysis(FMEA)isastep-by-stepapproachforidentifyingallpossiblefailuresinadesign,amanufacturingorassemblyprocess,oraproductorservice.失效模式及效果分析是一個按部就班地識別存在于設(shè)計、制造或組裝過程，或一個產(chǎn)品或效勞中的全部可能的失效的方法“Failuremodes〞meanstheways,ormodes,inwhichsomethingmightfail.Failuresareanyerrorsordefects,especiallyonesthataffectthecustomer,andcanbepotentialoractual.“失效模式〞表示某些事務(wù)可能失效的形式或模式。失效是指任何錯誤或缺陷，特別是那些影響到顧客的錯誤或缺陷。既可以是潛在的，也可以是實際的。“Effectsanalysis〞referstostudyingtheconsequencesofthosefailures.“效果分析〞是指研究這些失效的后果。4FMEADescriptionFMEA描述Failuresareprioritizedaccordingtohowserioustheirconsequencesare,howfrequentlytheyoccurandhoweasilytheycanbedetected.ThepurposeoftheFMEAistotakeactionstoeliminateorreducefailures,startingwiththehighest-priorityones.根據(jù)效果的嚴重程度、發(fā)生的頻次以及探測的難易程度把失效列出先后順序。失效模式及效果分析就是要從最優(yōu)先的工程開始消除或減少失效。AnFMEAalsodocumentscurrentknowledgeandactionsabouttherisksoffailures,foruseincontinuousimprovement.FMEAisusedduringdesigntopreventfailures.Laterit’susedforcontrol,beforeandduringongoingoperationoftheprocess.Ideally,FMEAbeginsduringtheearliestconceptualstagesofdesignandcontinuesthroughoutthelifeoftheproductorservice.失效模式及效果分析還記錄下當前的知識和對于失效風險所采取的措施，以便用于持續(xù)改進。它首先用于設(shè)計以防止失效。然后把它用于過程開始前以及過程中的控制。理想的情況是，在設(shè)計的最早期概念階段就開始失效模式及效果分析，然后貫穿產(chǎn)品或效勞的整個過程。5WHATisFMEA?FMEA是什么?FMEAisforFailureModeandEffectsAnalysisFMEA是失效模式及效果分析的縮寫Systematicactivities是系統(tǒng)化的活動Recognizeandevaluatepotentialfailureofaproductoraprocessandtheeffectsofthatfailure發(fā)現(xiàn)和評價一個產(chǎn)品或一個過程的潛在失效以及該失效的效果Identifyactionsthatcanbetakentoeliminate,reduce,orpreventcostlyfailures識別出能夠采取的措施以消除、減少或防止費用高昂的失效Emphasizetheimportanceandactionofprevention強調(diào)預防的重要性以及預防措施Documenttheentireprocess將整個過程文件化6FMEAfocusesondesignofproductorprocessFMEA關(guān)注于產(chǎn)品或過程的設(shè)計DesignFMEA設(shè)計失效模式及效果分析〔DFMEA〕ProcessFMEA過程失效模式及效果分析〔PFMEA〕TheindustrieswhichnormallyuseFMEA通常使用FMEA的行業(yè)Aviationandspaceflight:Lowvolume,withcomplexsystem,processandproduct,highreliabilityrequirements.航空航天工業(yè)：小批量，但系統(tǒng)、過程和產(chǎn)品復雜，可靠性要求高。Locomotiveindustryisclosetoaviationandspaceflightindustry.機車工業(yè)與航空航天工業(yè)接近。Automobile:Highvolume,withcomplexsystem,processandproduct,highimpacttobothcustomersandmanufacturers.汽車工業(yè)：大批量，且系統(tǒng)、過程和產(chǎn)品復雜，對顧客和制造商的影響大。WHATisFMEA?FMEA是什么?Tobediscussedindetailinthissession將在本次課程中詳細討論7WHYthePFMEAisnecessary?為什么做PFMEA?Identifywhataprocessmustdotosatisfythecustomer明確過程必須做什么才能使顧客滿意Identifypotentialproblemswhichcouldaffectthequalityofparts.找到那些潛在的可能影響零件的質(zhì)量的問題Developprioritizecontrolplansforcorrectiveactions為糾正措施制定有優(yōu)先順序的控制方案Monitorpotentialconcernsduringtheproductmanufacturingplanningstagesofacomponent在零件的制造過程方案階段對潛在的擔憂進行監(jiān)控8WHYthePFMEAisnecessary?為什么做PFMEA?Thereare3basicreasonsfordoingaFMEA啟動FMEA有三種根本原因Newdesigns,newtechnology,ornewprocess.新設(shè)計、新技術(shù)或新過程Thescopeistocompletethedesign,technology,orprocess其范圍是完成設(shè)計、技術(shù)或過程Modificationstoexistingdesignorprocess對現(xiàn)有設(shè)計或過程進行變更AssumesoriginalFMEAalreadyexists.Thescopeistotoimprovethedesign,orprocess假設(shè)已經(jīng)存在一個初始的FMEA。其范圍是改進設(shè)計或過程。Useofanexistingdesignorprocessinanewenvironment,location,orapplication將一個現(xiàn)有設(shè)計或過程用于一個新環(huán)境、地點或應(yīng)用AssumesoriginalFMEAalreadyexists.Thescopeistheimpactofthenewenvironmentorlocationwithexistingdesignorprocess假設(shè)初始FMEA已經(jīng)存在。此時研究范圍變?yōu)樾颅h(huán)境或地點對現(xiàn)有設(shè)計或過程的影響。9WHYthePFMEAisnecessary?為什么做PFMEA?Generalindustrytrendistoalwaysimproveproductsandprocess.行業(yè)的總體趨勢是總要不斷地改善產(chǎn)品和過程FMEAisdesignedtohelpminimizepotentialconcerns設(shè)計FMEA這種方法是為了有助于最大限度地降低潛在的擔憂Mustbea“before-the-event〞not“after-the-event〞activity必須是一項“事先的〞而不是“事后的〞的活動Mustdobeforeaprocessfailuremodehasbeenincorporatedintoaproductorprocess必須在一個過程失效模式在過程中發(fā)生之前進行SpendingtimetodoappropriateFMEAupfrontcanmodifytheproductandprocesseasierandunderlowercost事先花時間適當?shù)赝瓿蒄MEA分析能夠更容易、低本錢地對產(chǎn)品和過程進行更改Thehigherlossresultedfromthelateprevention/correctionactionscanbereducedoreliminated減少或消除事后采取預防/糾正措施而帶來的更大損失10WHYthePFMEAisnecessary?為什么做PFMEA?MeetCustomerRequirement滿足顧客要求ImproveProductQuality改進產(chǎn)品質(zhì)量MaintainCompetitionPosition維護競爭地位Reducetheriskoffailure減小失效的風險11PFMEABenefitsPFMEA的好處Capturesthecollectiveknowledgeofateam獲得整個小組的集體智慧Improvesthequality,reliability,andsafetyoftheprocess改善過程的質(zhì)量、可靠性和平安性Logical,structuredprocessforidentifyingprocessareasofconcern用來識別過程中令人擔憂之處的縝密而結(jié)構(gòu)化的過程Reducesprocessdevelopmenttimeandcost減少過程開發(fā)時間和費用HelpstoidentifyCritical-To-Qualitycharacteristics(CTQs)有助于識別影響質(zhì)量的關(guān)鍵特性12PFMEABenefitsPFMEA的好處Provideshistoricalrecords;establishesbaseline提供歷史數(shù)據(jù)，建立基準Helpsincreasecustomersatisfactionandsafety有助于提高顧客滿意度和平安性Improvescompanyimageandcompetitiveness改善公司形象，提高競爭力Documentsandtracksactiontakentoreducerisk記錄和追蹤為降低風險所采取的措施ReducespotentialforWarrantyconcerns降低潛在的關(guān)于質(zhì)量擔保的擔憂13WHOwilldothePFMEA?-TeamEffort誰來做PFMEA?-團隊合作Usuallynotjustonepersontotallyresponsible.TheFMEAshouldbeateameffort.通常不是由一個人負全部責任。FMEA應(yīng)當是一個團隊活動。Engineer/TeamwhoisresponsibleforManufacturingshouldtaketheleadofPFMEA.負責制造的工程師或團隊應(yīng)領(lǐng)導進行PFMEA。Teammustbeknowledgeable小組成員必須具有豐富經(jīng)驗Engineerswithexpertiseindesign,analysis/testing,manufacturing,assembly,service,recycling,quality,andreliability.具有設(shè)計、分析/試驗、制造、組裝、效勞、回收再利用、質(zhì)量和可靠性經(jīng)驗的工程師ItishelpfultohaveanexperiencedFMEAfacilitatorassisttheteaminitsactivities.如果讓一個有經(jīng)驗的FMEA推進者在活動中對小組提供協(xié)助將會很有幫助。14WHENFMEAwillbeused何時使用FMEADuringtheAPQP(AdvancedProductQualityPlanning)在產(chǎn)品質(zhì)量先期籌劃期間DFMEAisimplementedduringProductDesign&DevelopmentDFMEA在產(chǎn)品設(shè)計和開發(fā)階段應(yīng)用PFMEAisimplementedduringProcessDesign&DevelopmentPFMEA在過程設(shè)計和開發(fā)階段應(yīng)用Planning策劃ProductDesign&Development產(chǎn)品設(shè)計和開發(fā)ProcessDesign&Development過程設(shè)計和開發(fā)ProductandProcessValidation產(chǎn)品與過程確認Production生產(chǎn)Feedback,Assessment&CorrectiveAction反饋、評價和糾正措施Conceptinitiate/approval概念提出及批準Projectapproved項目批準Prototype樣件Pre-production試生產(chǎn)Productionlaunch投產(chǎn)Planning策劃DFMEAPFMEA15ThescopeofPFMEAPFMEA的覆蓋范圍Thebackboneisasequentiallistingoftheprocesssteps,calledtheProcessFlowDiagram.Itgenerallydescribesprocessactivities.主干是一個有順序的被稱為過程流程圖的工藝步驟清單。它通常描述過程的活動。Takeintoaccountallprocessesintheactivity,frommaterialreceivingtoproductdelivery.考慮活動當中從材料接收到成品發(fā)運的整個過程。Takeintoaccountallmanufacturingoperations,fromindividualscomponentstoassemblies.考慮從單個零件到總成的全部加工過程。e.g.loadpart,drillhole,performleaktest,assemblepart例如，裝卡零件，鉆孔，進行試漏，裝配零件等Allprocessstepsandassociatedfailuremodeswhichcouldresultinadefecttotheproductshouldbeconsidered.所有過程步驟和相關(guān)的能夠?qū)е庐a(chǎn)品缺陷的失效模式都應(yīng)加以考慮。16Identifiestheprocessfunctionsandrequirements識別過程的功能和要求Identifiespotentialprocess-relatedfailuremodes識別潛在的與過程有關(guān)的失效模式Assessestheeffectsofthepotentialfailuresonthecustomer評價潛在失效模式對顧客的影響Identifiesthepotentialmanufacturingorassemblyprocesscausesandidentifiesprocessvariablesonwhichtofocuscontrolsforoccurrencereductionordetectionofthefailureconditions,識別潛在的制造或組裝過程原因并識別出那些需要對其進行控制以便降低失效發(fā)生的頻度或探測度的過程變量Developsarankedlistofpotentialfailuremodes,thusestablishingaprioritysystemforpreventative/correctiveactionconsiderations,and開發(fā)一個潛在失效模式分級清單并為預防和糾正措施建立一個優(yōu)先系統(tǒng)Documentstheresultsofthemanufacturingorassemblyprocess.記錄制造或組裝過程的結(jié)果HOWtodothePFMEA?怎樣做PFMEA?17Whatisthefunction,featureorrequirement?功能、特征或要求是什么？Whatistheeffect?影響是什么？Whatisthepotentialfailure?可能有何錯誤？Howsevere?有多嚴重？Whatisthereason?起因是什么？Whatistheoccurrence?發(fā)生的幾率如何？Isitpreventableanddetectable?這有可能預防和探測嗎？Howgoodisthedetectionmethod?探測方法有多好？Whatcanbedone?可以做什么？HOWtodothePFMEA?怎樣做PFMEA?Itisnotjustacasethatfillingintheform!它不僅僅是填滿表格！18BeforedoingaPFMEA在做FMEA之前Assumestheproductasdesignedwillmeetthedesignintent.假設(shè)所設(shè)計的產(chǎn)品符合設(shè)計意圖DesignweaknessmaybeincludedinthePFMEA.However,thedesigneffectandavoidanceiscoveredbytheDesignFMEA.設(shè)計上的缺陷有可能包括在PFMEA中。但是，設(shè)計缺陷的效果及防止方法將包括在DFMEA中。PFMEAdoesnotrelyonproductdesignchangestoovercomeweaknessesintheprocess.PFMEA不依賴改變產(chǎn)品設(shè)計來克服過程中的缺陷。ButPFMEAdoestakeintoaccountaproduct‘sdesigncharacteristicsrelativetotheplannedmanufacturingorassemblyprocesstoassurethat,totheextentpossible,theresultantproductmeetscustomerneedsandexpectations.但PFMEA要考慮與相對于方案中的制造或組裝過程相應(yīng)的產(chǎn)品設(shè)計特性。要盡最大可能確保所得到的產(chǎn)品滿足顧客的需要和希望。19BeforedoingaPFMEA在做FMEA之前Equipmentmustbedesignedtobecapable.設(shè)備的設(shè)計必須是具備能力的。Thecommoncauseproblemsarewithinthetolerancesoftheprocess;thereforeonlyspecialcausesaregenerallyconsideredintheProcessFMEA.一般原因造成的問題是在過程的誤差范圍內(nèi)。在進行PFMEA過程中通常只考慮特殊原因。Assumestheselectedmaterialsarecorrect假設(shè)所選擇的材料是正確的20BeforedoingaPFMEA在做FMEA之前Setupthecross-functionalteam建立橫向協(xié)調(diào)小組Process-responsibleengineershouldhavefollowingdocumentsavailable負責過程的工程師應(yīng)該能得到以下這些文件Listofwhattheprocessisexpectedtodoandnotdo.(processintent)關(guān)于希望過程做什么不做什么的清單〔過程的目的〕FlowChartofthegeneralprocess(defineproduct/processcharacteristicsassociatedwitheachoperation)整個過程的流程圖〔確定與每個過程相關(guān)的產(chǎn)品/過程特性〕KeepprocessflowwithFMEAdocumentation將流程圖與FMEA文件保存在一起IdentificationofsomeproducteffectsfromthecorrespondingDesignFMEA(ifavailable)〔如果可能，〕從相應(yīng)的DFMEA中識別出產(chǎn)品的一些功能。Makesuresufficienttimeavailabletoevaluatethewholeprocess確保有足夠的時間對整個過程進行評估21BeforedoingaPFMEA在做FMEA之前Collecthistoricalin-housequalityinspectiondata收集既往內(nèi)部檢查記錄ListentoVoiceofCustomer傾聽顧客的呼聲Historicalwarrantydata既往保修數(shù)據(jù)Customerrejecteddefectiveproduct顧客退還的缺陷產(chǎn)品Customersurveyandvisit顧客調(diào)查/訪問Competitoranalysis競爭對手分析Customercomplain顧客的抱怨VeryusefulfortheselectingofSeverity,OccurrenceandDetectionrating對于選擇嚴重度、頻度和探測度的等級非常有用22BeforedoingaPFMEA在做FMEA之前UnderstandtheInterfacesandInteractionsamongtheSystem,Subsystem,andComponent理解系統(tǒng)、子系統(tǒng)和零件的接口和相互作用Note:EachsubsystemFMEAshouldhaveitsinterfacesincludedinitsrespectiveSubsystemFMEA.注：每個子系統(tǒng)的FMEA都應(yīng)將其接口包括在各自的FMEA中。SubsystemA子系統(tǒng)ASubsystemB子系統(tǒng)BSubsystemD子系統(tǒng)DSubsystemC子系統(tǒng)CEnvironment環(huán)境23BeforedoingaPFMEA在做FMEA之前Interactions:AChangeinonesubsystemmightcauseachangeinanothersubsystem相互作用：一個子系統(tǒng)內(nèi)的變化可能引起另一個子系統(tǒng)內(nèi)的變化。SubsystemA子系統(tǒng)ASubsystemB子系統(tǒng)BSubsystemD子系統(tǒng)DSubsystemC子系統(tǒng)CEnvironment環(huán)境Interactionsbetweensubsystemscanoccuramonganyoftheinterfacingsystems兩個子系統(tǒng)之間的相互作用可以發(fā)生在任何有接口關(guān)系的系統(tǒng)之間。FurnaceConsiderinteractionsbetweennon-contactingsystems考慮非接觸系統(tǒng)之間的相互作用24DevelopmentofaProcessFMEA

一個PFMEA的開發(fā)PreparetheProcessFlowDiagram準備過程流程圖25DevelopmentofaProcessFMEA

一個PFMEA的開發(fā)Step1第一步Step2第二步Step3第三步Step4第四步Step5第五步Step6第六步Step7第七步Followthestepstofillintheform按照步驟填寫表格26DevelopmentofaProcessFMEA–Step1

一個PFMEA的開發(fā)–第一步FMEANumberFMEA編號EnterFMEADocumentnumber,whichmaybeusedfortracking.填入FMEA的編號，該編號可以被用來查詢。Item工程名稱Enterthename&numberofthesystem,subsystem,orcomponentforwhichtheprocessisbeinganalyzed.填入將要被分析的系統(tǒng)、子系統(tǒng)或零部件的名稱和編號。ProcessResponsibility過程責任Enterthenameofdepartmentand/orgroupwhoisresponsiblefortheprocess.填入負責該過程的相關(guān)部門和/或小組的名稱27PreparedBy編制者Enterthename,telephonenumber,andcompanyoftheengineerresponsibleforpreparingtheFMEA.填入負責準備FMEA的責任工程師的姓名、號碼和公司名稱ModelYear(s)/Program(s)車型年度/工程Entertheintendedmodelyearand/orprogramname填入預期的車型年度和/或產(chǎn)品工程名稱KeyDate關(guān)鍵日期EntertheinitialFMEAduedate,whichshouldnotexceedthescheduledstartofproductiondate.填入初次FMEA預計的完成日期。該日期不應(yīng)超過方案開始生產(chǎn)的日期。DevelopmentofaProcessFMEA–Step1

一個PFMEA的開發(fā)–第一步28FMEADateFMEA日期EnterdatetheoriginalFMEAwascompiledandlastupdated填入初次FMEA的編制日期以及上一次修訂日期CoreTeam核心小組Listallnamesofresponsibleindividuals列出全部負有責任的個人的姓名Teammembername,phoneanddepartment小組成員姓名、和部門DevelopmentofaProcessFMEA–Step1

一個PFMEA的開發(fā)–第一步29DevelopmentofaProcessFMEA–Step2

一個PFMEA的開發(fā)–第二步ProcessFunction/Requirements過程功能/要求Enterasimpledescriptionoftheprocessandoperationnumber輸入過程的一個簡單描述及工序號Reviewtheapplicableperformance,materials,safetystandards評審適用的性能、材料、平安標準Simplydescribetheintentoftheoperation簡單地描述過程的功能Listtheelementsseparatelyifmultiplefailuremodesexistedintheoperation(suchasassembly)如果過程包括許多具有不同潛在失效模式的作業(yè)〔例如裝配〕，那么把這些作業(yè)單獨列出。30DevelopmentofaProcessFMEA–Step2

一個PFMEA的開發(fā)–第二步CoverageofProcessSteps過程步驟的覆蓋范圍Exclude–Non-processactivities不包括與過程無關(guān)的活動e.g.automatedconveyorssystems,storageofparts,coolantdump,inspectionofparts例如，自動化的傳送帶系統(tǒng)，零件的儲存，冷卻液的傾倒，零件的檢查。Includeactivitiesrelatedtoprocesssteps.包括與過程步驟有關(guān)的活動e.g.gluepattern,addalloys,puremetal,millsurface例如，粘結(jié)型板，添加合金，提純金屬，銑外表.Includeactivitiesrelatedtoancillarystationsthatcontributetofinalcharacteristicsoftheproduct.包括與有助于形成產(chǎn)品最終特性有關(guān)的輔助工位上的活動e.g.partwashstations,shaftstraighteners例如，零件的清洗工位，軸的校直裝置31Theprocesscouldpotentiallyfailtomeettheprocessrequirementsand/ordesignintentasdescribedintheprocessfunction/requirementscolumn.

過程可能潛在地不滿足過程功能/要求中所描述的過程要求和/或設(shè)計意圖。Itisthedescriptionofthenon-conformanceatthatspecificoperation.

是對特定過程出現(xiàn)不合格現(xiàn)象的描述。Itcanbeconnectedwithaoperationthatmayoccurdownstreamorapreviousoperation.

可以與下一道工序或前一道工序聯(lián)系起來。

Itcouldbeareasonofafailureofdownstreamoperationoraresultoffailurefrompreviousoperation.它可能是下一道工序失效模式的起因或是前一道工序失效模式的結(jié)果。DevelopmentofaProcessFMEA–Step3

一個PFMEA的開發(fā)–第三步PotentialFailureMode

潛在失效模式32Listeachpotentialfailuremode(couldoccurbutmaynotnecessarilyoccur)fortheparticularoperationintermsofacomponent,subsystem,system,orprocesscharacteristic.對于一個零件、子系統(tǒng)、系統(tǒng)或過程特性的特定工序列出每種潛在失效模式〔可能發(fā)生，但不一定發(fā)生〕。Typicalquestionsshouldbeposedandansweredbytheprocessengineerand/orteam:過程工程師和/或小組應(yīng)該提出并答復的典型問題：Howcantheprocess/partfailtomeetspecifications?過程/零件怎么不能滿足要求？Regardlessofengineeringspecifications,whatwouldbeacustomer(enduser,subsequentoperationsorservice)considerobjectionable?不管工程標準是如何規(guī)定的，顧客〔最終使用者、后續(xù)工序或效勞〕會提出什么疑義？DevelopmentofaProcessFMEA–Step3

一個PFMEA的開發(fā)–第三步PotentialFailureMode

潛在失效模式33Typicalfailuremodes:典型失效模式DevelopmentofaProcessFMEA–Step3

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