1、Process Failure Mode and Effects Analysis(Process FMEA)SCOPE DEFINITION(Step 1)Company Name:Name of company responsible for PFMEASubject:Name of PFMEA projectSystem/sub-system/component/part:Name of system elementPlant Location:Geographical locationPFMEA Start Date:Date PFMEA project startedPFMEA ID
2、 Number:Determined by the companyCustomer Name:Name of customer(s)or product family PFMEA Revision Date:Date of most recent changeProcess Responsibility:Name of PFMEA ownerModel Year/Platform:Customer application or company model/styleCross-Functional Team:Team Roster neededConfidentiality Level:Bus
3、iness Use,Confidential,Propriotary,etc.STRUCTURE ANALYSIS(Step 2)FUNCTION ANALYSIS(Step 3)FAILURE ANALYSIS(Step 4)RISK ANALYSIS(Step 6)OPTIMIZATION(Step 6)RemarksCONTINUOUSIMPROVEMENT1.Process ItemSystem,Subsystem,PartElement or Name of Process2.Process StepStation No.and Name of FocusElement3.Proce
4、ss Work Element Man,Machine,Material(Indirect),Milieu(Environment),etc.1.Function of the Process Item In-plant,Ship to plant,ProcessItem,Vehicle End user,whenknown 2.Function of the Process Stepand Product Characteristic(Quantitative value is optional)3.Function of the Process WorkElement and Proces
5、sCharacteristic1.Failure Effects(FE)In-plant,ship to plant,processitem,vehicle end user,whenknowOriginal Severity(S)of FE2.Failure Mode(FM)of theProcess Element3.Failure Cause(FC)of the WorkElementCurrent PreventionControl(PC)of FCOccurrence(O)of FCCurrent DectectionControls(DC)of FC orFMDetection(D
6、)of FC/FMAction Priority(AP)Special Product CharFilter Code(optional)Prevention ActionDetection ActionResponsiblePersonTargetCompletionDate(TCD)Status:Open,Completed,DiscardedAction Takenwith Pointerto EvidenceCompletionDateSeverity(S)Occurrence(O)Detection(D)Action Priority(AP)History/ChangeAuthori
7、zation(AsApplicable)The name of the process beinganalyzed e.g.electrical motorassembly line which is the endresult of all successfullycompleted process stepsmay also be a non-directmanufacturing process e.g.shippingThe operation or station to beanalyzed that produces theProcess Item e.g.OP30 Sintere
8、dbearing Press-in processUse the 4Ms to identity types ofvariation that have an influenceon the operation or station beinganalyzed4M Types:Man,Machine,Material(indirect),Milieu(Environment)List a single M for each line.Types may vary by companyA description of what theProcess Item is expected toachi
9、eve broken down intoseveral categoriesSome categories maybeunknown and listed as NotApplicable(NA)These expectations can bereferred to when completingFailure Effects(FE)These expected results mayapply for the entire Process Iteme.g.electrical motor assemblylineIn-plant：Avoid rework andscrapShip to p
10、lant Installation ofwindow lifter electrical motor tovehicle doorProcess Item.：Shaft installedinto pole house assemblyVehicle.：Window raises andlowersA description of what theoperation or station mustachieve e.g.Axial positionsintered bearing in pole housingThis is the positive ProductCharacteristic
11、 and must bedetectable in the productThe Failure Mode or FailureModes will be the negative ornegatives of the positive ProductCharacteristic.The Product Characteristic canbe written stating the entirepositive Product Characteristic,eg within gap tolerance,or usingseparate lines,considering overand u
12、nder tolerance,e g,notgreater then max tolerance,notless than min tolerance.It mayalso consider magnitude of outto tolerance if it effects theFailure Effects e.g.gap notgreater then max tolerance by03mm or gap not greater thenmax tolerance-More than 3 mmA positive description of how thework is compl
13、eted including thepositive process characteristicrelated to each 4MThe negative of these positiveswill be used for the FailureCause column The more detailused here will produce moreFailure Cause i.e.each line is aunique positive producing aunique negative,i.e.a FailureCauseInstead of“Get correct sin
14、teredbearing from part rack and placeinto fixture”Use“Get correctsintered bearing”and“Fullyplace bearing into fixture”Thisidentifies of two separate FailureCauses,i.e.“wrong part picked”“Bearing not fully set into fixture”The more detail used,the moreCauses can be captured in thedocumented for risk
15、analysis.Other possible positive processcharacteristic-“Pick part frompart rack without scratching thetop surface”,“Place part intofixture without using too muchforce”.Apply torque to bolt untilgreen light appears.Applytorque to bolt until green lightappears but not beyond.“Pickcorrect lubrication”.
16、“Applycorrect volume of lubrication”New Product Characteristicand Failure Modes-Whileconsidering“Function of theProcess Work Element andProcess Characteristic”new“Product Characteristics”.“Failure Causes”and“FailureModes”maybe generated,i.e.listing.“Pick part from part rackwithout scratching the top
17、surface”,may generate a newFailure Cause.“Scratched topsurface while picking part fromrack”and a new“ProductCharacteristics”,“Top surfacescratch free”and new FailureMode“Top surface scratched”How the Vehicle,System orSubsystem could fail to performthe Function described at theNext Higher levelWhen c
18、onsidering Effects,consider items listed in“Functionof the Process Item”and theFailure Mode”end how they canEffect the 3 areas beingconsidered(In-Plant,Ship toplant.Process Item,Vehicle EndUser)Include potential effects to thevehicle(End User)level endregulations.as applicableIt is recommended to li
19、st theSeverity Rank next to each ofthe 3 areas being consideredand use the highest Rank for theSeverity Rank.One area,suchas End User.may not alwayshave the highest Severity Rank110Failure mode must be detectablein the product(defect)The Failure Mode will be thenegative or negatives of thepositive P
20、roduct Characteristic.Considering each side of thespecification of ProductCharacteristic if specification ofProduct Characteristic has arange,list Failure Mode for eachside of the specification,i.e.,“Torque Bolt to spec”,the FailureModes will be“Torque loss thenspec”,“Torque more than spec”Each may
21、have a differentSeverity Rank.Considering magnitude of out ofspecification If the magnitude ofout of specification can affect theSeverity Rank.It should helisted,i.e.,“No stamping cracks”,the Failure Modes could becrack 0-10 mm long”,SeverityRank 4.“Crack greater than 10mm but less than 20 mm long”.
22、Severity Rank 7.“Crack 20 mmor greater”Severity Rank 10.Each will have its ownOccurrence Ranks.Controls,etc.When using a spreadsheet toperform the Failure Analysis it isrecommended to begin withFailure Modes then identifyFailure Effects and Causes.The Failure Cause is thenegative of the positive lis
23、ted in“Function of the Process WorkElement and ProcessCharacteristic”Cause must be detectable in theprocess(error)and lead to theFailure ModeNew Failure Causes-Whileconsidering“Failure Causes”,new Function of the ProcessWork Element and ProcessCharacteristic”,“ProductCharacteristic and maybegenerate
24、d,i.e.listing.“Scratchedtop surface while picking partfrom rack”can generate“Pickpart from part rack withoutscratching the top surface”,maygenerate and a new“ProductCharacteristics”,“Top surfacescratch tree”and a new FailureMode“Top surface scratched”Failure Analysis can begin withthe FM.FF or FC as
25、 long asthere is an accurate FailureChainInitial State-Pastcontrols proven and/orcontrols committed to110Initial State-Pastcontrols proven and/orcontrols committed to110H,M,L,NALLAdditional Actionsneeded to reduceOccurrenceAdditional Actionsneeded to improveDetectionName,nottitle ordepartmentmm yy o
26、r ddmm yyOptional:Decisionpending,Implementation pendingDescription ofaction takenanddocumentnumber,report nameand date,etc.mm yy or ddmm yy110 110 110 H,M,L,NAFor PFMEAteam useExamples:A design change:DCN0983885A managementreview:MR07-NOV-2017A customerreview:CR02-FEB-2018Electrical MotorOP 30 Sint
27、ered bearing pressOperatorProcess Item:Convert electricalenergy into mechanical energy(acc.control signal)In Plant:Assembly ofcomponents within cycle time,without scrap or reworkShip to Plant:Assembly of motorto vehicle door without linestoppage,sort or containmentEnd User Window raises andlowersPre
28、ss in sintered bearing toachieve axial position in polehousing to max gap per printOperator takes clean sinteredbearing from chute and push itonto the press-in shaft until theupper stopProcess Item:Loss ofmechanical energy because oftoo much friction betweenbearing and shaft,inner diameterof the bea
29、ring deformed becauseoff too much seating stressIn Plant:NoneShip to Plant NoneEnd User:Window raises andlowers with difficulty8Axial position of sintered bearingis not reached,gap too smallOperator inserts a sinteredbearing which was dropped tothe ground floor before(contaminated with dirt)No Preve
30、ntion control10Lot release Protectobjective(effectiveity100%)Visual Gaugeinspection of axial gapof bearing to polehousing eat by operator(check the checker:N/A)Dectection indicator:OK/NOK(RED/GREENarea)and operatorseparate the NOK part2HCCThe definition of awork instruction anda work instruction for
31、falling componentsand contents of theregularTraining curricularthe operator andfinishing staffJohn Doe(ProductionEngineer)DD.MM.YYYYIn-progress832LElectrical MotorOP 30 Sintered bearing pressMachine(press machine)Process Item:Convert electricalenergy into mechanical energy(acc.control signal)In Plan
32、t:Assembly ofcomponents within cycle time,without scrap or reworkShip to Plant:Assembly of motorto vehicle door without linestoppage,sort or containmentEnd User Window raises andlowersPress in sintered bearing toachieve axial position in polehousing to max gap per printMachine has to press in thesin
33、tered bearing into the polehousing seat until the definedaxial positionProcess Item:Loss ofmechanical energy because oftoo much friction betweenbearing and shaft,inner diameterof the bearing deformed becauseoff too much seating stressIn Plant:NoneShip to Plant NoneEnd User:Window raises andlowers wi
34、th difficulty8Axial position of sintered bearingis not reached,gap too smallMachine stops before reachingfinal position(too less force)Selected press withforce monitoring andposition control sensor3Lot release Protectobjective(effectiveity100%)Visual Gaugeinspection of axial gapof bearing to polehou
35、sing eat by operator(check the checker:N/A)2M3Electrical MotorOP 30 Sintered bearing pressMachine(press machine)Process Item:Convert electricalenergy into mechanical energy(acc.control signal)In Plant:Assembly ofcomponents within cycle time,without scrap or reworkShip to Plant:Assembly of motorto ve
36、hicle door without linestoppage,sort or containmentEnd User.Window raises andlowersPress in sintered bearing toachieve axial position in polehousing to max gap per printMachine has to press in thesintered bearing into the polehousing seat until the definedaxial positionProcess Item:NoneIn Plant:Asse
37、mbly of shaft is notpossible because clearance toosmall (scrap 7),excessive linecycle time(7)Ship to Plant:n/aEnd User:n/a7axial position of sintered bearingis not reached,gap too largeMachine stops before reachingfinal position(too less force)Selected press withforce monitoring andposition control
38、sensor3Lot release Protectobjective(effectiveity100%)Visual Gaugeinspection of axial gapof bearing to polehousing eat by operator(check the checker:N/A)Dectection indicator:OK/NOK(RED/GREENarea)and operatorseparate the NOK part3M3missed contexts in draft handbookProcessProcess FailureFailure ModeMod
39、e andand EffectsEffects AnalysisAnalysis (Process(Process FMEA)FMEA)过过程程失失效效模模式式及及效效果果分分析析(过过程程FMEA)FMEA)步步骤骤1 1：范范围围定定义义公司名称：负责PFMEA的 公司任务描述：PFMEA项目名称系统/子系统/部件名称:系统零部件的名称工厂地点：地理位置PFMEA开始日期：PFMEA开始日期PFMEA编号：按公司内部规定顾客名称：顾客名或过程族名称PFMEA修订日期：最新修订日期过程负责人：即PFMEA负责人车型年/平台：顾客车型年型/平台/款型跨职能小组：小组名单保密等级：例如：对外/机
40、密/内部使用步步骤骤2 2：结结构构分分析析步步骤骤3 3：功功能能分分析析步步骤骤4 4：失失效效分分析析步步骤骤5 5：PFMEAPFMEA 风风险险分分析析步步骤骤6 6：优优化化备注持续改进1.过程项目系统、子系统、零部件要素，或过程名称2.过程步骤工作站编号和关注要素名称3.作业要素（人、机、料（间接）、环，等等）1.过程项目的功能（内部工厂、客户工厂、过程项目、车辆用户，如果信息可获取的话）2.过程步骤的功能和产品特性（可用量化数据）3.作业要素的功能和过程特性1.失效影响(FE)（内部工厂、客户工厂、过程步骤、车辆用户，如果信息可获取的话）严重度（FE)2.过程步骤的失效模式(F
41、M)3.作业要素的失效原因(FC)当前针对FC的预防性控制措施(PC)FC发生度(O)当前针对FC或FM的探测性控制措施(DC)FC/FM 探测度(D)AP（行动优先级）特殊特性过滤代码（可选）预防措施探测措施责任人目标完成日期状态（进行中/完成/取消）采取的措施和降低分值的证据实际完成日期更新严重度(S)更新发生度(O)更新探测度(D)更新PFMEA AP历史/变更授权（如适用）要分析的过程名称，例如电机装配线，其是所有过程步骤的集合。也可以是非制造过程，例如发运要分析的操作或工位，这些用以组成过程，例如OP 30轴承压入工序采用4M法来识别影响所分析的操作或工位的差异来源。4M：人、机器、
42、物料（非直接物料）、环境。公司可自行选择其它方法描述过程所要实现或达成的内容，可分成几类。如果未知的话就写NA。这些所要实现或达成的内容其实可在失效分析(FE)完成后进行倒推。以下例子可用于整个过程，例如电机装配线内部工厂：避免返工和报废；客户工厂：摇窗机电机安装到车门上；过程：装入总成壳体；车辆：升降车窗玻璃描述操作或工位要实现什么：例如轴承在电机机壳的轴向位置。这是明确的产品特性，必须能在产品上被探测到。失效模式将是这些产品特性的不足。产品特性可描述成满足要求规范，例如在间隙公差范围内，或不超过公差上下限。考虑到失效影响(FE)的程度，或许也以此种形式表述：不超过间隙上公差03mm，或最多
43、不能大于上公差3mm描述作业应当是如何完成的，包括与4M相应的过程特性。对应的不足将填写在失效原因(FC)列。越细化能对应出越多的失效原因，也就是说一个不足就是一个失效原因。例如“从料箱拿轴承并放入制具”，如果换种形式表述“拿取正确轴承”+“把轴承完全放入制具”，这样就能对应出两个失效原因，即“拿取错误轴承”和“轴承未完全放入制具”。描述地越细，则有越多的原因，以便下一步分析。其它可能的过程特性-“从料箱拿轴承时不刮伤表面”，“轴承放入制具中时不用太大力”，“拧紧螺栓直到扭矩灯亮绿”，“拧紧螺栓直到扭矩灯亮绿，此时不能再用力”，“拿取正确的润滑油”，“涂正确量润滑油”。新新的的产产品品特特性性
44、和和失失效效模模式式-当考虑“作业要素的功能和过程特性”时，新的“产品特性”、“失效原因”和“失效模式”可能会产生，比如“从料箱拿轴承时不刮伤表面”就可能对应出新的失效原因“从料箱拿轴承时刮伤表面”、新的产品特性“上端面无划痕”、新的失效模式“上端面刮伤”车辆、系统或子系统如何不能实现（上一层级）功能要求。当分析影响时，要考虑“过程功能”里的内容和“失效模式”，以及如何影响这三个方面（内部工厂、客户工厂、过程步骤、车辆用户）。如适用，还要考虑法律法规的不符合情况。建议对这三个方面分别进行严重度打分，并选择其中最大的分数。对车辆用户的影响的严重度分值不一定是最高的。110失效模式（不良/缺陷）必
45、须是在产品中可探测的。失效模式其实也是产品特性的不足。如果产品特性有规范上下限的话，要分别考虑上下限的失效模式，例如“螺栓拧紧扭矩满足规范”，对应失效模式为“扭矩低于下限”和“扭矩高于上限”，两者对应的严重度可能是不一样的。考虑超出规范的量级，如果超出的量级影响严重度的话。例如“无冲压裂纹”，失效模式可能是“裂纹长度010mm”-严重度4，“裂纹长度1020mm”-严重度7，“裂纹长度20mm以上”-严重度10。其有各自对应的发生度和控制措施。当使用FMEA Excel表时，建议先从失效模式开始分析，然后是失效影响和失效原因。失效原因是“作业要素的功能和过程特性”中相应的不足。原因必须是过程中
46、可探测的（错误），是导致失效模式的。新失效原因-当考虑“失效原因”时，新的“作业要素的功能和过程特性”、“产品特性”和“失效模式”可能会产生，比如“从料箱拿轴承时刮伤表面”就可能对应出“从料箱拿轴承时不刮伤表面”、新的产品特性“上端面无划痕”、新的失效模式“上端面刮伤”。失效分析可从失效模式、失效影响或失效原因开始，假如失效链是精确的话。已实施的和/或确定要实施的控制措施110已实施的和/或确定要实施的控制措施110H,M,L,NACCLL降低O值的额外措施降低D值的额外措施填具体人姓名，不是部门年月日或：待决定/待实施采取的措施以及文件号，汇报人及日期，等等年月日110110110H,M,L
47、,NA供PFMEA小组使用例如：已对HighAP进行了评审，基于已实施的预防性和探测性控制措施，认为无需额外行动措施例如：设计变更DCN098385，管理层评审 MR07-NOV-2017，顾客评审 CR02-FEB-2018玻璃升降电机总成OP#30压入球面轴承作业员过程：按控制信号转化电能为机械能；内部工厂：在周期时间内装配，无报废和返工；客户工厂：电机安装到车门不会出现停线/停顿、拣选、遏制；用户：升降车窗玻璃在电机壳里压入球面轴承，轴向位置在图纸公差允许范围内作业员从料箱拿取正确型号的清洁的球面轴承，并放到压机的上止位过程：机械能损失，因为球面轴承与转子间摩擦过大，球面轴承与轴承座过紧
48、使得球面轴承内尺寸变形（8）；内部工厂：无客户工厂：无；用户：车窗玻璃升降困难(7)8 轴承轴向位置没有达到，间距过小作业员使用之前掉到过地上的轴承（轴承上有异物）无#批次放行要求（100%有效），检验员用检具检查球面轴承与电机座的间距，用绿色和红色记号笔标记OK/NOK件，再由作业员筛选。3HCC作业指导书规定不允许使用掉到地上的轴承，并培训相关人员JohnDoe(生产工程师）进行中玻璃升降电机总成OP#30压入球面轴承作业员过程：按控制信号转化电能为机械能；内部工厂：在周期时间内装配，无报废和返工；客户工厂：电机安装到车门不会出现停线/停顿、拣选、遏制；用户：升降车窗玻璃在电机壳里压入球面
49、轴承，轴向位置在图纸公差允许范围内作业员从料箱拿取正确型号的清洁的球面轴承，并放到压机的上止位过程：机械能损失，因为球面轴承与转子间摩擦过大，球面轴承与轴承座过紧使得球面轴承内尺寸变形（8）；内部工厂：由于间距小，转子装配困难（报废)(7），周期时间超时（7）；客户工厂：无；用户：车窗玻璃升降困难(7)8 轴承轴向位置没有达到，间距过小作业员拿了错误型号的轴承料箱门根据轴承型号自动打开；作业指导书；作业员培训1 批次放行要求（100%有效），检验员用检具检查球面轴承与电机座的间距，用绿色和红色记号笔标记OK/NOK件，再由作业员筛选。无法继续装配1L玻璃升降电机总成OP#30压入球面轴承机器（
50、压机）过程：按控制信号转化电能为机械能；内部工厂：在周期时间内装配，无报废和返工；客户工厂：电机安装到车门不会出现停线/停顿、拣选、遏制；用户：升降车窗玻璃在电机壳里压入球面轴承，轴向位置在图纸公差允许范围内压机把球面轴承压入电机壳至规定的轴向位置过程：机械能损失，因为球面轴承与转子间摩擦过大，球面轴承与轴承座过紧使得球面轴承内尺寸变形（8）；内部工厂：由于间距小，转子装配困难（报废)(7），周期时间超时（7）；客户工厂：无；用户：车窗玻璃升降困难(7)8 轴承轴向位置没有达到，间距过小压机在还没压到位就停止了（压力太小）使用带有压力和位置传感器的压机3 批次放行要求（100%有效），检验员用
