过程失效模式及后果分析(PFMEA)(ppt 61)中英文

1、PFMEAProcess Failure Mode and Effects Analysis过程失效模式及后果分析过程失效模式及后果分析(PFMEA)PFMEA陶 国PFMEAProprietary Information专有信息专有信息w Your FMEA (Control Plan, Process Capability, etc.) may be considered proprietary and should not be shared with anyone outside the division without first consulting your management

2、. FMEA (控制计划、过程能力等) 可视为专有信息，在未事先 征得管理部门同意之前，不得向部门以外的任何人透露。E this includes the sharing of information with your customer也不得向顾客透露有关信息。PFMEAForms and Formats形式和格式形式和格式w Your customer might have a specific format or form that they require. If so, you will need to get their written approval to use an alt

3、ernate format. 顾客可能要求特定的格式或表单。如果是这样，你只有征得他们的书面同意，才能采用其它格式。PFMEAProcess FMEA过程过程FMEAw何谓PFMEAw何时作PFMEAw何人作PFMEAw如何作PFMEAw16步工作步骤PFMEAProcess FMEA过程过程FMEAw何时作PFMEAw何人作PFMEAw如何作PFMEAw16步工作步骤PFMEAProcess FMEA过程过程FMEAwan analytical tool used by a process design team to identify potential product failures

4、caused by failure of the manufacturing and assembly process to meet requirements, and identify corrective actions to be taken 是过程设计小组采用的一种分析方法，用于识别由于制造或装配过程的失效而导致的潜在产品失效模式，并确定所应采取的纠正措施。PFMEAwformal process正式程序wcustomer focused着眼于顾客wuses engineering judgment, and hard data where it is available利用工程经验

5、判断和可靠的数据Process FMEA过程过程FMEAPFMEAwPFMEA is focussed on the PFMEA 关注对的影响Process FMEA过程过程FMEAPFMEAProcess FMEA过程过程FMEAw何谓PFMEAw何人作PFMEAw如何作PFMEAw16步工作步骤PFMEAWhen do we do a PFMEA?何时进行何时进行PFMEA？wWhile there is still time to bring about changes in the process and in the product! 当还有时间修改产品及工艺设计时！wA PFMEA

6、 done solely to fill out a form and meet “requirements” is just an exercise为了满足QS9000要求而填写PFMEA表格，仅是练习而已PFMEAwPFMEA is an output of the Process Design and Development phase of APQP PFMEA是APQP中“过程设计和开发”阶段的产物When do we do a PFMEA?何时进行何时进行PFMEA？PFMEAwIt is derived from a DFMEA在DFMEA之后进行EAny DFMEA forms

7、 and supporting documents shoud be brought to the PFMEA meetingsDFMEA表单和所有相关文件都应带入PFMEAwIt should be a natural part of concept development 应成为过程设计的一个必要组成部分wPFMEA is never “finished”.it is a living document 是动态文件When do we do a PFMEA?何时进行何时进行PFMEA？PFMEAWhen do we do a PFMEA?何时进行何时进行PFMEA？PFMEAWhen do

8、 we do a PFMEA?何时进行何时进行PFMFA？PFMEAProcess FMEA过程过程FMEAw何谓PFMEAw何时作PFMEAw如何作PFMEAw16步工作步骤PFMEAWho performs a PFMEA?由谁进行由谁进行PFMEA？wA cross-functional team should be used由跨部门小组进行wThe leader should be the process-responsible engineer小组组长应是过程设计责任工程师PFMEACross-Functional Team跨部门小组跨部门小组w 5-9 people from，5-

9、9人，由从事如下工作的人员组成 E Design，设计 E Assembly，装配E manufacturing (operators, supervisors)，制造 (操作工，班组长)E Industrial, mfg. And tool engineering，工业工程，工艺及工装设计E quality，质量管理E materials engineering，材料工程E Service personnel，机修E Supplier of product and machinery，零件和设备供应商E Representatives from the next process, 后续工序代

10、表PFMEAProcess FMEA过程过程FMEAw何谓PFMEAw何时作PFMEAw何人作PFMEAw16步工作步骤PFMEAHow do we do a PFMEA? A Summary怎样进行怎样进行PFMEA？提要？提要w Assemble the cross-functional PFMEA team组建跨部门PFMEA小组w List the failure modes, their effects, and their causes列出失效模式，后果以及原因PFMEAw Assess，评估 Ethe severity of the effect (S) 后果的严重程度Ethe

11、likelihood of the causes (O) 原因出现的可能性Eand the ability of process controls to detect failure modes and/or their causes (D)过程控制探测失效模式和/或原因的能力How do we do a PFMEA? A Summary怎样进行怎样进行PFMEA？提要？提要PFMEAwCalculate the risk priority number (RPN) to prioritize corrective actions 计算风险顺序数(RPN)以确定应优先采取的纠正措施wPlan

12、corrective actions and assign owner制订纠正措施并落实责任人wPerform corrective actions to improve the product or process, 采取纠正措施以提高产品和过程质量wRecalculate RPN重新估算RPNHow do we do a PFMEA? A Summary怎样进行怎样进行PFMEA？提要？提要PFMEAHow do we do a PFMEA?A Suggestion怎样进行怎样进行PFMEA？建议？建议w Do your work on scratch paper first; as th

13、e team reaches consensus, record the information on the FMEA form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E use fishbone and tree diagrams liberally 充分利用鱼刺图和树形图E trying to use the FMEA form as a worksheet leads to confusion and messed-up FMEAs 若将FMEA表当做工作单使用，就会造成混乱，使FMEA一塌糊涂PFMEAProcess FMEA过程过程FMEAw何谓

14、PFMEAw何时作PFMEAw何人作PFMEAw如何作PFMEAPFMEA1. Assemble a team and plan your activities成立小组并制订计划成立小组并制订计划w PFMEA must never be done by an individual, because 绝不能由个人单独进行PFMEA，因为： Eindividual efforts produce biased results,由个人进行会使结果出现偏差Eany actions will require buy-in from various groups进行任何活动，都需要从不同的组织取得信息P

15、FMEAw One person (e.g. the leader) should be assigned to maintaining the FMEA form 应指定一个人(如组长)保管FMEA表格EBe sure to write the names and functions of the team members on the FMEA form应将小组成员的姓名和职责填入FMEA表格1. Assemble a team and plan your activities成立小组并制订计划成立小组并制订计划PFMEA2. Develop a process flow diagram

16、绘制过程流程图绘制过程流程图wUse the Process Flow Diagram format 运用正规的过程流程图Eidentifies fabricate, move, store and inspect operations 辨别四种作业类型Eidentifies Key Characteristics辨别关键特性PFMEA Supplier_Date_Part Number_Revision Level_Part Description_ Prepared by_pressuremold partfabmove store inspstepoper. descr.item#KPC

17、item#KCCinspect partfor flashstore part in containercarry parts to assy area1no flash112342. Develop a process flow diagram 绘制过程流程图绘制过程流程图PFMEAmold part注塑零部件注塑零部件fab加工加工move搬运搬运store存放存放insp检验检验step步骤步骤oper. descr.作业说明作业说明item#编号编号KPCitem#编号编号KCCinspect partfor flash检验零件有无飞边检验零件有无飞边store part in con

18、tainer将零部件放入周转箱内将零部件放入周转箱内carry parts to assy area将零部件送往装配区将零部件送往装配区1no flash无飞边无飞边pressure压力压力11234PFMEAPFMEA3. List the function(s) of each operation列出每个操作的功能列出每个操作的功能w A function is what the operation does 功能系指该操作所起的作用 w State the function as， 说明功能为： mold part，零件成型 crimp terminal onto cable 在线端压接

19、端子 form bend in part, 零件弯曲成型examples例如PFMEAwDont forget auxiliary functions as well a primary functions基本功能和辅助功能都要考虑3. List the function(s) of each operation列出每个操作的功能列出每个操作的功能PFMEA4. List the quality requirements列出质量要求列出质量要求w a customer want or desire顾客的希望或要求w could seriously affect customer percept

20、ion有可能严重影响顾客的看法 w could lead to a customer complaint 有可能导致顾客投诉PFMEA5. List the potential process failure modes 列出可能的过程失效模式列出可能的过程失效模式w a defect, flaw, or other unsatisfactory condition in the product that occurs when the process fails to meet the process requirements由于过程未达到要求而导致的产品缺陷、瑕疵等不良状态Efailure

21、 modes should be written in terms of the condition of the product失效模式体现在产品上PFMEAw Typical Failure Modes，几种典型失效模式Ediameter out of spec.，直径超差Emissing seal，漏装密封垫Ecut strands，切破线皮Emisoriented part，部件方向错Einsufficient solder，焊剂不足Etoo much solder，焊剂过量ENFO，未充满EFlash，飞边5. List the potential process failure m

22、odes 列出可能的过程失效模式列出可能的过程失效模式PFMEAw Note，注 EAssume that incoming product and materials are correct假设来料没问题EAssume that the product as designed will meet requirements假设产品设计能够满足客户需求5. List the potential process failure modes 列出可能的过程失效模式列出可能的过程失效模式PFMEA6. Derive the potential effects of each failure 列出每一失

23、效模式的所有可能后果列出每一失效模式的所有可能后果w The ramifications of failure后果是失效模式的衍生事件 w The effect can be on ，可能影响Ethe ultimate customer，最终用户Eor intermediate customer (OEM, etc.)，中间用户Ea government regulation ，法规Ethe next process step，下序PFMEAw Customer complaints are a useful source of information顾客抱怨是非常有用的信息来源6. Deri

24、ve the potential effects of each failure 列出每一失效模式的所有可能后果列出每一失效模式的所有可能后果PFMEAw An effect can be，后果可能为 Ecomplete loss of function，功能完全丧失 Edegradation of performance or quality，质量或性能降低Edamage of process equipment，设备受损Einjury to an operator，员工受伤Eshut-down of an assembly line，停线6. Derive the potential ef

25、fects of each failure 列出每一失效模式的所有可能后果列出每一失效模式的所有可能后果PFMEAw Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer，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w It is recommended that these chains be developed for each failure mode and recorded on the

26、FMEA form 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Euse a tree diagram运用树形图6. Derive the potential effects of each failure 列出每一失效模式的所有可能后果列出每一失效模式的所有可能后果PFMEAEffects on the process，对过程的影响:w 9-10may endanger machine or operator，可能导致设备或人员受损w 6-8scrap，报废w 4-5sort and rework，检验、返工w 2-3rework on-line，线上返工w 1no effe

27、ct，无影响7. Assess the severity of each effect评估每种后果的严重度评估每种后果的严重度PFMEACriteria: Severity of EffectThis ranking results when a potential failure mode results in a final customer and/or a manufacturing/assembly plant defect. The final customer should always be considered first. If both occur, use the hi

28、gher of the two sevHazardous-without warning10Very high severity ranking when a potential failure mode affects safe vehicle operation and/or involves noncompliance with government regulation without warning.Or may endanger operator (machine or assembly) without warning.Hazardous-with warning9Very hi

29、gh severity ranking when a potential failure mode affects safe vehicle operation and/or involves noncompliance with government regulation with warning.Or may endanger operator (machine or assembly) with warning.Very High8Vehicle/item inoperable (loss of primary function).Or 100% of product may have

30、to be scrapped, or vehicle/item repaired in repair department with a repair time greater than one hour.High7Vehicle/item operable but at a reduced level of performance. Customer very dissatisfied.Or product may have to be sorted and a portion (less than 100%) scrapped, or vehicle/item repaired in re

31、pair department with a repair time between a half-hour and an one hour.Moderate6Vehicle/item operable but Comfort/Convenience item(s) inoperable. Customer dissatisfied.Or a portion (less than 100%) of the product may have to be scrapped with no sorting, or vehicle/item repaired in repair department

32、with a repair time less than a half-hour.Low5Vehicle/item operable but Comfort/Convenience item(s) operable at reduced level of performance.Or 100% of product may have to be reworked, or vehicle/item repaired off-line but does not go to repair department. Very Low4Fit & Finish/Squeak & Rattl

33、e item does not conform. Defect noticed by most customers (greater than 75%).Or the product may have to be sorted, with no scrap, and a portion (less than 100%) reworked.Minor3Fit & Finish/Squeak & Rattle item does not conform. Defect noticed by 50% of customers.Or a portion (less than 100%)

34、 of the product may have to be reworked, with no scrap, on-line but out-of-station.Very Minor2Fit & Finish/Squeak & Rattle item does not conform. Defect noticed by discriminating customers (less than 25%).Or a portion (less than 100%) of the product may have to be reworked, with no scrap, on

35、-line but in-station.None1No discernible effect.Or slight incovenience to operation or operator, or no effect.PFMEA8. Determine potential cause(s) of each failure mode 确定每一失效模式的可能原因确定每一失效模式的可能原因w A cause of failure is how the failure can occur in the process，失效原因：过程为何会失效EShould be written in terms o

36、f something in the process that can be ，应表述为的因素EConsider human error, wear-out of tools, ambient conditions, and interactions of factors，如人的过失，工装磨损、环境条件以及因素间的相互作用PFMEAw Causes of failure often show up as a chain of events, from immediate cause to root cause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w It is recommend

37、ed that these chains be developed for each failure mode and recorded on the FMEA form建议针对每一种失效模式，找出原因链，记入FMEA表Euse a tree or fishbone diagram to develop可利用树形图或鱼刺图8. Cause(s) of Failure失效原因失效原因PFMEA9. Assess the likelihood of occurrence of each cause评估每种失效原因产生的可能性评估每种失效原因产生的可能性w Use historical data (

38、as a baseline) ，利用历史资料E Take improvements into account，并考虑所作的改进 w Use statistical models and comparison with similar processes利用可靠性模型，与类似的过程进行比较PFMEA9-10 Failure almost inevitable，失效几乎不可避免7-8Similar processes that have often failed in the past，以前类似过程常常失效4-6Similar processes that have occasional fail

39、ures，类似过程偶尔失效1-3Similar processes that have experienced isolated failures，类似过程仅有过个别失效9. Assess the likelihood of occurrence of each cause评估每种失效原因产生的可能性评估每种失效原因产生的可能性PFMEAOccurence (O)ProbabilityLikely Failure Rates*Very High: Persistent Failures= 100 per thousand piecesVery High: Persistent Failures

40、50 per thousand piecesHigh: Frequent Failures20 per thousand piecesHigh: Frequent Failures10 per thousand piecesModerate: Occasional Failures5 per thousand piecesModerate: Occasional Failures2 per thousand piecesModerate: Occasional Failures1 per thousand piecesLow: Relatively Few Failures0.5 per th

41、ousand piecesLow: Relatively Few Failures0.1 per thousand piecesRemote: Failure is Unlikely= 0.010 per thousand pieces10987654321PFMEACauses and EffectsHarness ClampCause-and-effect chainradius out of spectool is worntool notreplacedlack of maintenance procedureclamp cracksat bendbundle falls outrat

42、tling noiseCAUSE chainEFFECT chainPFMEACauses and EffectsWiring AssemblyEffects TreeCrossed WireNofunctionFire in PlantOperatorInjuryDamagedEquip.Must repair vehiclePFMEACauses and EffectsWiring AssemblyCauses TreeCrossed WireBoardErrorOperatorErrorPoorInstruct.NottrainedOper istiredPFMEA10. List th

43、e Current Process Controls列出现有过程控制列出现有过程控制w Process controls catch the defect before the product reaches the customer，过程控制当在产品到达顾客前发现缺陷!w There are three Types of process controls, 过程控制有三种类型:1. (1) prevent the cause of failure, or reduce the rate of occurrence，防止原因出现或降低其出现的可能性2. (2) detect the cause

44、(s) of failure and lead to corrective actions，查明失效的原因并找出纠正措施3. (3) detect the failure mode(s)，检测失效模式PFMEAw Assign currently used process controls to failure modes and causes，针对失效模式或原因列出现行的过程控制手段EUsed on similar processes in the past，以前类似过程如何控制ECan be of any Type: 1, 2, or 3, or any combination，可以是1、

45、2、3类或其组合EType 1 controls affect the likelihood of occurrence, if already part of the design，若设计中已有体现，则第1类方法可降低原因出现的频度EIf none, write “None” ，若没有，则填“无”。10. List the Current Process Controls列出现有过程控制列出现有过程控制PFMEAw Detection is an assessment of the probability that，探测度为下列事件发生的概率Ea type 2 control can det

46、ect the cause and lead to corrective action, 第2类控制能够发现原因并找到纠正措施Ea type 3 control can detect a failure，第3类控制能够在不良品到达顾客前发现缺陷. before the product reaches the customer!Edetection can also assess how effectively a type 1 control can prevent failure，第1类控制能够预防失效的有效程度11. Detecting failure探测度探测度PFMEA11. Dete

47、cting failure探测度探测度Detection Rating (D)，探测度评分(D)9-10very remote chance this control will detect the cause or failure查明失效或其原因的可能性极小7-8remote chance ，可能性很小5-6moderate to low chance ，可能性不大2-4moderately to very high chance ，可能性较大 1almost certainly (if the part passes this test, its OK to ship)几乎都可以查到(如能

48、通过这项检测，则可放心发货)PFMEADetection (D)CriteriaInspectionTypesSuggested Range of Detection MethodsABCAlmost ImpossibleAbsolute certainty of non-detection.XCannot detect or is not checked.Very RemoteControls will probably not detect.XControl is achieved with indirect or random checks only.RemoteControls hav

49、e poor chance of detection.XControl is achieved with visual checks only.Very LowControls have poor chance of detection.XControl is achieved with double visual inspection only.LowControls may detect.XXControl is achieved with charting methods, such as SPC Statistical Process Control.ModerateControls

50、may detect.XControl is based on variable gauging after parts have left the station, or Go/No Go gauging performed on 100% of the parts after parts have left the station.Moderately HighError detection is in subsequent operations, OR gauging performed on setup and first-piece check (for set-up causes

51、only).Controls have a good chance to detect.XXHighError detection in-station, or error detection in subsequent operations by multiple layers of acceptance: supply, select, install, verify. Cannot accept descrepant part.Controls have a good chance to detect.XXVery HighControls almost certain to detec

52、t.XXError detection in-station (automatic gauging with automatic stop feature). Cannot pass discrepant part.Very HighControls certain to detect.XDiscrepant parts cannot be made because item has been error-proofed by process/product design.Inspection Types: A. Error-proofed, B. Gauging, C. Manual InspectionPFMEA12. Calculate