1、,Process Failure Mode and Effects Analysis過(guò)程失效模式及后果分析(PFMEA)PFMEAPFMEA,陶 國(guó),Proprietary Information專有信息,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. FMEA (控制計(jì)劃、過(guò)程能力等

2、) 可視為專有信息，在未事先 征得管理部門同意之前，不得向部門以外的任何人透露。 this includes the sharing of information with your customer 也不得向顧客透露有關(guān)信息。,Forms and Formats形式和格式,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 alternate format. 顧客可能要求特定的格式或表

3、單。如果是這樣，你只有征得他們的書面同意，才能采用其它格式。,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,Process FMEA過(guò)程FMEA,an analytical tool used by a process design team to identify potential product failures caused by failure of the manufacturing

4、 and assembly process to meet requirements, and identify corrective actions to be taken 是過(guò)程設(shè)計(jì)小組采用的一種分析方法，用于識(shí)別由于制造或裝配過(guò)程的失效而導(dǎo)致的潛在產(chǎn)品失效模式，并確定所應(yīng)采取的糾正措施。,formal process 正式程序 customer focused 著眼于顧客 uses engineering judgment, and hard data where it is available 利用工程經(jīng)驗(yàn)判斷和可靠的數(shù)據(jù),Process FMEA過(guò)程FMEA,PFMEA is foc

5、ussed on the Product PFMEA 關(guān)注對(duì)產(chǎn)品的影響,Process FMEA過(guò)程FMEA,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,When do we do a PFMEA?何時(shí)進(jìn)行PFMEA？,While there is still time to bring about changes in the process and in the product! 當(dāng)還有時(shí)間修改產(chǎn)品及工藝設(shè)計(jì)時(shí)！ A PFMEA done solely to fill out a form and meet “

6、requirements” is just an exercise 為了滿足QS9000要求而填寫PFMEA表格，僅是練習(xí)而已,PFMEA is an output of the Process Design and Development phase of APQP PFMEA是APQP中“過(guò)程設(shè)計(jì)和開(kāi)發(fā)”階段的產(chǎn)物,When do we do a PFMEA?何時(shí)進(jìn)行PFMEA？,It is derived from a DFMEA 在DFMEA之后進(jìn)行 Any DFMEA forms and supporting documents shoud be brought to the PFM

7、EA meetings DFMEA表單和所有相關(guān)文件都應(yīng)帶入PFMEA It should be a natural part of concept development 應(yīng)成為過(guò)程設(shè)計(jì)的一個(gè)必要組成部分 PFMEA is never “finished”.it is a living document 是動(dòng)態(tài)文件,When do we do a PFMEA?何時(shí)進(jìn)行PFMEA？,Do a PFMEA (or at least review the old one) if: 以下情況需進(jìn)行PFMEA(或至少評(píng)審過(guò)去的PFMEA) ： the process is new 是新的過(guò)程 the

8、product is new, or has never been made with this process 新產(chǎn)品，或從未用本過(guò)程加工的產(chǎn)品 an existing process changes 原有的過(guò)程發(fā)生變化 customer requirements or desires change 顧客要求或希望發(fā)生變化,When do we do a PFMEA?何時(shí)進(jìn)行PFMEA？,Do a PFMEA (or at least review the old one) if: 以下情況需進(jìn)行PFMEA(或至少評(píng)審過(guò)去的PFMEA)： the competitive, business,

9、 or legal environment changes 競(jìng)爭(zhēng)環(huán)境、業(yè)務(wù)環(huán)境或法律環(huán)境發(fā)生變化 PPAP conditions apply 需提交PPAP actual failures occur 發(fā)生實(shí)際失效,When do we do a PFMEA?何時(shí)進(jìn)行PFMFA？,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,Who performs a PFMEA?由誰(shuí)進(jìn)行PFMEA？,A cross-functional team should be used 由跨部門小組進(jìn)行 The leader should

10、 be the process-responsible engineer 小組組長(zhǎng)應(yīng)是過(guò)程設(shè)計(jì)責(zé)任工程師,Cross-Functional Team跨部門小組,5-9 people from，5-9人，由從事如下工作的人員組成 Design，設(shè)計(jì) Assembly，裝配 manufacturing (operators, supervisors)，制造 (操作工，班組長(zhǎng)) Industrial, mfg. And tool engineering，工業(yè)工程，工藝及工裝設(shè)計(jì) quality，質(zhì)量管理 materials engineering，材料工程 Service personnel，機(jī)修

11、Supplier of product and machinery，零件和設(shè)備供應(yīng)商 Representatives from the next process, 后續(xù)工序代表,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,How do we do a PFMEA? A Summary怎樣進(jìn)行PFMEA？提要,Assemble the cross-functional PFMEA team 組建跨部門PFMEA小組 List the failure modes, their effects, and their ca

12、uses 列出失效模式，后果以及原因,Assess，評(píng)估 the severity of the effect (S) 后果的嚴(yán)重程度 the likelihood of the causes (O) 原因出現(xiàn)的可能性 and the ability of process controls to detect failure modes and/or their causes (D) 過(guò)程控制探測(cè)失效模式和/或原因的能力,How do we do a PFMEA? A Summary怎樣進(jìn)行PFMEA？提要,Calculate the risk priority number (RPN) to

13、 prioritize corrective actions 計(jì)算風(fēng)險(xiǎn)順序數(shù)(RPN)以確定應(yīng)優(yōu)先采取的糾正措施 Plan corrective actions and assign owner 制訂糾正措施并落實(shí)責(zé)任人 Perform corrective actions to improve the product or process, 采取糾正措施以提高產(chǎn)品和過(guò)程質(zhì)量 Recalculate RPN 重新估算RPN,How do we do a PFMEA? A Summary怎樣進(jìn)行PFMEA？提要,How do we do a PFMEA?A Suggestion怎樣進(jìn)行PFMEA

14、？建議,Do your work on scratch paper first; as the team reaches consensus, record the information on the FMEA form 先在一張草稿紙上進(jìn)行分析；當(dāng)小組達(dá)成一致意見(jiàn)后，再將有關(guān)信息填在FMEA表上 use fishbone and tree diagrams liberally 充分利用魚刺圖和樹形圖 trying to use the FMEA form as a worksheet leads to confusion and messed-up FMEAs 若將FMEA表當(dāng)做工作單使用

15、，就會(huì)造成混亂，使FMEA一塌糊涂,Process FMEA過(guò)程FMEA,何謂PFMEA 何時(shí)作PFMEA 何人作PFMEA 如何作PFMEA 16步工作步驟,1. Assemble a team and plan your activities成立小組并制訂計(jì)劃,PFMEA must never be done by an individual, because 絕不能由個(gè)人單獨(dú)進(jìn)行PFMEA，因?yàn)椋?individual efforts produce biased results, 由個(gè)人進(jìn)行會(huì)使結(jié)果出現(xiàn)偏差 any actions will require buy-in from va

16、rious groups 進(jìn)行任何活動(dòng)，都需要從不同的組織取得信息,One person (e.g. the leader) should be assigned to maintaining the FMEA form 應(yīng)指定一個(gè)人(如組長(zhǎng))保管FMEA表格 Be sure to write the names and functions of the team members on the FMEA form 應(yīng)將小組成員的姓名和職責(zé)填入FMEA表格,1. Assemble a team and plan your activities成立小組并制訂計(jì)劃,2. Develop a proc

17、ess flow diagram 繪制過(guò)程流程圖,Use the Process Flow Diagram format 運(yùn)用正規(guī)的過(guò)程流程圖 identifies fabricate, move, store and inspect operations 辨別四種作業(yè)類型 identifies Key Characteristics 辨別關(guān)鍵特性,Supplier_Date_ Part Number_Revision Level_ Part Description_Prepared by_,pressure,2. Develop a process flow diagram 繪制過(guò)程流程圖,

18、過(guò)程流程圖,3. List the function(s) of each operation列出每個(gè)操作的功能,A function is what the operation does 功能系指該操作所起的作用 State the function as， 說(shuō)明功能為： Verb + Object + Qualifier 動(dòng)詞+賓語(yǔ)+修飾詞 mold part，零件成型 crimp terminal onto cable 在線端壓接端子 form bend in part, 零件彎曲成型,examples例如,Dont forget auxiliary functions as well

19、a primary functions 基本功能和輔助功能都要考慮,3. List the function(s) of each operation列出每個(gè)操作的功能,4. List the quality requirements列出質(zhì)量要求,a customer want or desire 顧客的希望或要求 could seriously affect customer perception 有可能嚴(yán)重影響顧客的看法 could lead to a customer complaint 有可能導(dǎo)致顧客投訴,5. List the potential process failure mo

20、des 列出可能的過(guò)程失效模式,a defect, flaw, or other unsatisfactory condition in the product that occurs when the process fails to meet the process requirements 由于過(guò)程未達(dá)到要求而導(dǎo)致的產(chǎn)品缺陷、瑕疵等不良狀態(tài) failure modes should be written in terms of the condition of the product 失效模式體現(xiàn)在產(chǎn)品上,Typical Failure Modes，幾種典型失效模式 diameter o

21、ut of spec.，直徑超差 missing seal，漏裝密封墊 cut strands，切破線皮 misoriented part，部件方向錯(cuò) insufficient solder，焊劑不足 too much solder，焊劑過(guò)量 NFO，未充滿 Flash，飛邊,5. List the potential process failure modes 列出可能的過(guò)程失效模式,Note，注 Assume that incoming product and materials are correct 假設(shè)來(lái)料沒(méi)問(wèn)題 Assume that the product as designed

22、 will meet requirements 假設(shè)產(chǎn)品設(shè)計(jì)能夠滿足客戶需求,5. List the potential process failure modes 列出可能的過(guò)程失效模式,6. Derive the potential effects of each failure 列出每一失效模式的所有可能后果,The ramifications of failure 后果是失效模式的衍生事件 The effect can be on ，可能影響 the ultimate customer，最終用戶 or intermediate customer (OEM, etc.)，中間用戶 a g

23、overnment regulation ，法規(guī) the next process step，下序,Customer complaints are a useful source of information 顧客抱怨是非常有用的信息來(lái)源,6. Derive the potential effects of each failure 列出每一失效模式的所有可能后果,An effect can be，后果可能為 complete loss of function，功能完全喪失 degradation of performance or quality，質(zhì)量或性能降低 damage of proc

24、ess equipment，設(shè)備受損 injury to an operator，員工受傷 shut-down of an assembly line，停線,6. Derive the potential effects of each failure 列出每一失效模式的所有可能后果,Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer，失效的后果通常表現(xiàn)為從對(duì)顧客的直接影響到最終影響等一系列連鎖反應(yīng) It is re

25、commended that these chains be developed for each failure mode and recorded on the FMEA form 建議針對(duì)每一種失效模式找出這些連鎖反應(yīng)，并記錄在FMEA表上 use a tree diagram 運(yùn)用樹形圖,6. Derive the potential effects of each failure 列出每一失效模式的所有可能后果,Effects on the process，對(duì)過(guò)程的影響: 9-10may endanger machine or operator，可能導(dǎo)致設(shè)備或人員受損 6-8scra

26、p，報(bào)廢 4-5sort and rework，檢驗(yàn)、返工 2-3rework on-line，線上返工 1no effect，無(wú)影響 consider also the effects on the customer 還要考慮對(duì)顧客的影響,7. Assess the severity of each effect評(píng)估每種后果的嚴(yán)重度,8. Determine potential cause(s) of each failure mode 確定每一失效模式的可能原因,A cause of failure is how the failure can occur in the process，失

27、效原因：過(guò)程為何會(huì)失效 Should be written in terms of something in the process that can be corrected and controlled，應(yīng)表述為可糾正或可控制的因素 Consider human error, wear-out of tools, ambient conditions, and interactions of factors，如人的過(guò)失，工裝磨損、環(huán)境條件以及因素間的相互作用,Causes of failure often show up as a chain of events, from immedia

28、te cause to root cause 失效通常是由一連串的原因造成的，從直接原因到根本原因 It is recommended that these chains be developed for each failure mode and recorded on the FMEA form 建議針對(duì)每一種失效模式，找出原因鏈，記入FMEA表 use a tree or fishbone diagram to develop 可利用樹形圖或魚刺圖,8. Cause(s) of Failure失效原因,9. Assess the likelihood of occurrence of e

29、ach cause評(píng)估每種失效原因產(chǎn)生的可能性,Use historical data (as a baseline) ，利用歷史資料 Take improvements into account，并考慮所作的改進(jìn) Use statistical models and comparison with similar processes利用可靠性模型，與類似的過(guò)程進(jìn)行比較,9-10Failure almost inevitable，失效幾乎不可避免 7-8Similar processes that have often failed in the past，以前類似過(guò)程常常失效 4-6Simi

30、lar processes that have occasional failures，類似過(guò)程偶爾失效 1-3Similar processes that have experienced isolated failures，類似過(guò)程僅有過(guò)個(gè)別失效,9. Assess the likelihood of occurrence of each cause評(píng)估每種失效原因產(chǎn)生的可能性,Causes and EffectsHarness Clamp,Cause-and-effect chain,tool is worn,tool not replaced,lack of maintenance p

31、rocedure,clamp cracks at bend,bundle falls out,rattling noise,CAUSE chain,EFFECT chain,Causes and EffectsWiring Assembly,Effects Tree,Crossed Wire,No function,Fire in Plant,Operator Injury,Damaged Equip.,Must repair vehicle,Causes and EffectsWiring Assembly,Causes Tree,Crossed Wire,Board Error,Opera

32、tor Error,Poor Instruct.,Not trained,Oper is tired,10. List the Current Process Controls列出現(xiàn)有過(guò)程控制,Process controls catch the defect before the product reaches the customer，過(guò)程控制當(dāng)在產(chǎn)品到達(dá)顧客前發(fā)現(xiàn)缺陷! There are three Types of process controls, 過(guò)程控制有三種類型: (1) prevent the cause of failure, or reduce the rate of

33、occurrence，防止原因出現(xiàn)或降低其出現(xiàn)的可能性 (2) detect the cause(s) of failure and lead to corrective actions，查明失效的原因并找出糾正措施 (3) detect the failure mode(s)，檢測(cè)失效模式,Assign currently used process controls to failure modes and causes，針對(duì)失效模式或原因列出現(xiàn)行的過(guò)程控制手段 Used on similar processes in the past，以前類似過(guò)程如何控制 Can be of any Ty

34、pe: 1, 2, or 3, or any combination，可以是1、2、3類或其組合 Type 1 controls affect the likelihood of occurrence, if already part of the design，若設(shè)計(jì)中已有體現(xiàn)，則第1類方法可降低原因出現(xiàn)的頻度 If none, write “None” ，若沒(méi)有，則填“無(wú)”。,10. List the Current Process Controls列出現(xiàn)有過(guò)程控制,Detection is an assessment of the probability that，探測(cè)度為下列事件發(fā)生的

35、概率 a type 2 control can detect the cause and lead to corrective action, 第2類控制能夠發(fā)現(xiàn)原因并找到糾正措施 a type 3 control can detect a failure，第3類控制能夠在不良品到達(dá)顧客前發(fā)現(xiàn)缺陷 . before the product reaches the customer! detection can also assess how effectively a type 1 control can prevent failure，第1類控制能夠預(yù)防失效的有效程度,11. Detecti

36、ng failure探測(cè)度,11. Detecting failure探測(cè)度,Detection Rating (D)，探測(cè)度評(píng)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極小 7-8remote chance ，可能性很小 5-6moderate to low chance ，可能性不大 2-4moderately to very high chance ，可能性較大 1almost certainly (if the part passes this test,

37、its OK to ship) 幾乎都可以查到(如能通過(guò)這項(xiàng)檢測(cè)，則可放心發(fā)貨),12. Calculate the Risk Priority Number (RPN)計(jì)算風(fēng)險(xiǎn)順序數(shù)(RPN),RPN=S x O x D =Severity of Effect x Occurrence Rating x Detection Rating =后果的嚴(yán)重度 x 原因可能出現(xiàn)的頻度 x 探測(cè)度 Focus on high RPNs 關(guān)注RPN較高的項(xiàng)目,Recommended Corrective Action推薦的糾正措施,Aim for PREVENTION rather than detection 以預(yù)防而非探測(cè)為目的 Begin with the highest RPN items, 從RPN高的項(xiàng)目開(kāi)始 dont set an a priori “cut-off” value (i.e. prior to beginning the FMEA)，勿預(yù)先設(shè)定“分?jǐn)?shù)線” Give serious attention t