1、Process Failure Mode and Effects Analysis過程失效方式及后果分析(PFMEA)PFMEAPFMEA陶 國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 (控制方案、過程才干等) 可視

2、為專有信息，在未事先 征得管理部門贊同之前，不得向部門以外的任何人泄漏。this includes the sharing of information with your customer也不得向顧客泄漏有關信息。Forms and Formats方式和格式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. 顧客能夠要求特定的格式或表單。假設是這樣，

3、他只需征得他們的書面贊同，才干采用其它格式。Process FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟Process FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟Process FMEA過程FMEAan analytical tool used by a process design team to identify potential product failures caused by failure of the manufacturing and assembly process

4、to meet requirements, and identify corrective actions to be taken 是過程設計小組采用的一種分析方法，用于識別由于制造或裝配過程的失效而導致的潛在產品失效方式，并確定所應采取的糾正措施。formal process正式程序customer focused著眼于顧客uses engineering judgment, and hard data where it is available利用工程閱歷判別和可靠的數據Process FMEA過程FMEAPFMEA is focussed on the Product PFMEA 關注對

5、產品的影響Process FMEA過程FMEAProcess FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟When do we do a PFMEA?何時進展PFMEA？While there is still time to bring about changes in the process and in the product! 當還有時間修正產品及工藝設計時！A PFMEA done solely to fill out a form and meet “requirements is just an exercise為了滿足QS90

6、00要求而填寫PFMEA表格，僅是練習而已PFMEA is an output of the Process Design and Development phase of APQP PFMEA是APQP中“過程設計和開發階段的產物When do we do a PFMEA?何時進展PFMEA？It is derived from a DFMEA在DFMEA之后進展Any DFMEA forms and supporting documents shoud be brought to the PFMEA meetingsDFMEA表單和一切相關文件都應帶入PFMEAIt should be a

7、 natural part of concept development 應成為過程設計的一個必要組成部分PFMEA is never “finished.it is a living document 是動態文件When do we do a PFMEA?何時進展PFMEA？Do a PFMEA (or at least review the old one) if:以下情況需進展PFMEA(或至少評審過去的PFMEA) ：the process is new 是新的過程the product is new, or has never been made with this process新

8、產品，或從未用本過程加工的產品an existing process changes原有的過程發生變化customer requirements or desires change顧客要求或希望發生變化When do we do a PFMEA?何時進展PFMEA？Do a PFMEA (or at least review the old one) if:以下情況需進展PFMEA(或至少評審過去的PFMEA)：the competitive, business, or legal environment changes競爭環境、業務環境或法律環境發生變化PPAP conditions app

9、ly需提交PPAPactual failures occur發生實踐失效When do we do a PFMEA?何時進展PFMFA？Process FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟Who performs a PFMEA?由誰進展PFMEA？A cross-functional team should be used由跨部門小組進展The leader should be the process-responsible engineer小組組長應是過程設計責任工程師Cross-Functional Team跨部門小組5-9 p

10、eople from，5-9人，由從事如下任務的人員組成 Design，設計 Assembly，裝配manufacturing (operators, supervisors)，制造 (操作工，班組長)Industrial, mfg. And tool engineering，工業工程，工藝及工裝設計quality，質量管理materials engineering，資料工程Service personnel，機修Supplier of product and machinery，零件和設備供應商Representatives from the next process, 后續工序代表Proc

11、ess FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟How do we do a PFMEA? A Summary怎樣進展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 causes列出失效方式，后果以及緣由Assess，評價 the severity of the effect (S) 后果的嚴重程度the likelihood of the causes (O) 緣由出現

12、的能夠性and the ability of process controls to detect failure modes and/or their causes (D)過程控制探測失效方式和/或緣由的才干How do we do a PFMEA? A Summary怎樣進展PFMEA？提要Calculate the risk priority number (RPN) to prioritize corrective actions 計算風險順序數(RPN)以確定應優先采取的糾正措施Plan corrective actions and assign owner制定糾正措施并落實責任人P

13、erform corrective actions to improve the product or process, 采取糾正措施以提高產品和過程質量Recalculate RPN重新估算RPNHow do we do a PFMEA? A Summary怎樣進展PFMEA？提要How do we do a PFMEA?A Suggestion怎樣進展PFMEA？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

14、紙上進展分析；當小組達成一致意見后，再將有關信息填在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 假設將FMEA表當做任務單運用，就會呵斥混亂，使FMEA一塌糊涂Process FMEA過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步任務步驟1. Assemble a team and plan your activities成立小

15、組并制定方案PFMEA must never be done by an individual, because 絕不能由個人單獨進展PFMEA，由于： individual efforts produce biased results,由個人進展會使結果出現偏向any actions will require buy-in from various groups進展任何活動，都需求從不同的組織獲得信息One person (e.g. the leader) should be assigned to maintaining the FMEA form 應指定一個人(如組長)保管FMEA表格B

16、e sure to write the names and functions of the team members on the FMEA form應將小組成員的姓名和職責填入FMEA表格1. Assemble a team and plan your activities成立小組并制定方案2. Develop a process flow diagram 繪制過程流程圖Use the Process Flow Diagram format 運用正規的過程流程圖identifies fabricate, move, store and inspect operations 區分四種作業類型

17、identifies Key Characteristics區分關鍵特性 Supplier_Date_Part Number_Revision Level_Part Description_Prepared by_pressuremold partfabmovestoreinspstepoper. descr.item#KPCitem#KCCinspect partfor flashstore part in containercarry parts to assy area1no flash112342. Develop a process flow diagram 繪制過程流程圖過程流程圖

18、mold part注塑零部件fab加工move搬運store存放insp檢驗step步驟oper. descr.作業闡明item#編號KPCitem#編號KCCinspect partfor flash檢驗零件有無飛邊store part in container將零部件放入周轉箱內carry parts to assy area將零部件送往裝配區1no flash無飛邊pressure壓力112343. List the function(s) of each operation列出每個操作的功能A function is what the operation does 功能系指該操作所起的

19、作用 State the function as， 闡明功能為：Verb + Object + Qualifier 動詞+賓語+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 a primary functions根本功能和輔助功能都要思索3. List the function(s) of each operation列出每個操作的功能4. List the quality requir

20、ements列出質量要求a customer want or desire顧客的希望或要求could seriously affect customer perception有能夠嚴重影響顧客的看法 could lead to a customer complaint 有能夠導致顧客贊揚5. List the potential process failure modes 列出能夠的過程失效方式a defect, flaw, or other unsatisfactory condition in the product that occurs when the process fails t

21、o meet the process requirements由于過程未到達要求而導致的產品缺陷、瑕疵等不良形狀failure modes should be written in terms of the condition of the product失效方式表達在產品上Typical Failure Modes，幾種典型失效方式diameter out 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insufficient solder，焊劑缺乏too much solder，焊劑過量NFO，未充

22、溢Flash，飛邊5. List the potential process failure modes 列出能夠的過程失效方式Note，注 Assume that incoming product and materials are correct假設來料沒問題Assume that the product as designed will meet requirements假設產品設計可以滿足客戶需求5. List the potential process failure modes 列出能夠的過程失效方式6. Derive the potential effects of each f

23、ailure 列出每一失效方式的一切能夠后果The ramifications of failure后果是失效方式的衍惹事件 The effect can be on ，能夠影響the ultimate customer，最終用戶or intermediate customer (OEM, etc.)，中間用戶a government regulation ，法規the next process step，下序Customer complaints are a useful source of information顧客埋怨是非常有用的信息來源6. Derive the potential e

24、ffects of each failure 列出每一失效方式的一切能夠后果An effect can be，后果能夠為 complete loss of function，功能完全喪失 degradation of performance or quality，質量或性能降低damage of process equipment，設備受損injury to an operator，員工受傷shut-down of an assembly line，停線6. Derive the potential effects of each failure 列出每一失效方式的一切能夠后果Effects

25、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為從對顧客的直接影響到最終影響等一系列連鎖反響It is recommended that these chains be developed for each failure mode and recorded on the FMEA form 建議針對每一種失效方式找出這些連鎖反響，并記錄在FMEA表上use a tree diagram運用樹形圖6. Der

26、ive the potential effects of each failure 列出每一失效方式的一切能夠后果Effects on the process，對過程的影響:9-10may endanger machine or operator，能夠導致設備或人員受損6-8scrap，報廢4-5sort and rework，檢驗、返工2-3rework on-line，線上返工1no effect，無影響consider also the effects on the customer還要思索對顧客的影響7. Assess the severity of each effect評價每種后果

27、的嚴重度Criteria: 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 higher of the two sevHazardous-without warning10Very high severity

28、 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 high severity ranking when a potential failure mode affects safe v

29、ehicle 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 to be scrapped, or vehicle/item repaired in repair department wi

30、th 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 repair department with a repair time between a half-hour and an on

31、e 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 with a repair time less than a half-hour.Low5Vehicle/item operab

32、le 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 & Rattle item does not conform. Defect noticed by most customers (greater than

33、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%) of the product may have to be reworked, with no scrap, on-line but out-of-stati

34、on.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-line but in-station.None1No discernible effect.Or slight incovenience to operation or o

35、perator, or no effect.8. Determine potential cause(s) of each failure mode 確定每一失效方式的能夠緣由A cause of failure is how the failure can occur in the process，失效緣由：過程為何會失效Should be written in terms of something in the process that can be corrected and controlled，應表述為可糾正或可控制的要素Consider human error, wear-out

36、of tools, ambient conditions, and interactions of factors，如人的過失，工裝磨損、環境條件以及要素間的相互作用Causes of failure often show up as a chain of events, from immediate cause to root cause失效通常是由一連串的緣由呵斥的，從直接緣由到根本緣由It is recommended that these chains be developed for each failure mode and recorded on the FMEA form建議針

37、對每一種失效方式，找出緣由鏈，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失效緣由9. Assess the likelihood of occurrence of each cause評價每種失效緣由產生的能夠性Use historical data (as a baseline) ，利用歷史資料Take improvements into account，并思索所作的改良 Use statistical models and comparison with similar p

38、rocesses利用可靠性模型，與類似的過程進展比較9-10Failure almost inevitable，失效幾乎不可防止7-8Similar processes that have often failed in the past，以前類似過程經常失效4-6Similar processes that have occasional failures，類似過程偶爾失效1-3Similar processes that have experienced isolated failures，類似過程僅有過個別失效9. Assess the likelihood of occurrence

39、of each cause評價每種失效緣由產生的能夠性Occurence (O)ProbabilityLikely Failure Rates*Very High: Persistent Failures= 100 per thousand piecesVery High: Persistent Failures50 per thousand piecesHigh: Frequent Failures20 per thousand piecesHigh: Frequent Failures10 per thousand piecesModerate: Occasional Failures5

40、per thousand piecesModerate: Occasional Failures2 per thousand piecesModerate: Occasional Failures1 per thousand piecesLow: Relatively Few Failures0.5 per thousand piecesLow: Relatively Few Failures0.1 per thousand piecesRemote: Failure is Unlikely= 0.010 per thousand pieces10987654321Causes and Eff

41、ectsHarness ClampCause-and-effect chainradius out of spectool is worntool notreplacedlack of maintenance procedureclamp cracksat bendbundle falls outrattling noiseCAUSE chainEFFECT chainCauses and EffectsWiring AssemblyEffects TreeCrossed WireNofunctionFire in PlantOperatorInjuryDamagedEquip.Must re

42、pair vehicleCauses and EffectsWiring AssemblyCauses TreeCrossed WireBoardErrorOperatorErrorPoorInstruct.NottrainedOper istired10. List the Current Process Controls列出現有過程控制Process controls catch the defect before the product reaches the customer，過程控制當在產品到達顧客前發現缺陷!There are three Types of process cont

43、rols, 過程控制有三種類型:(1) prevent the cause of failure, or reduce the rate of occurrence，防止緣由出現或降低其出現的能夠性(2) detect the cause(s) of failure and lead to corrective actions，查明失效的緣由并找出糾正措施(3) detect the failure mode(s)，檢測失效方式Assign currently used process controls to failure modes and causes，針對失效方式或緣由列出現行的過程控

44、制手段Used on similar processes in the past，以前類似過程如何控制Can be of any Type: 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，假設設計中已有表達，那么第1類方法可降低緣由出現的頻度If none, write “None ，假設沒有，那么填“無。10. List the Current Process Controls列出現有過

45、程控制Detection is an assessment of the probability that，探測度為以下事件發生的概率a type 2 control can detect the cause and lead to corrective action, 第2類控制可以發現緣由并找到糾正措施a type 3 control can detect a failure，第3類控制可以在不良品到達顧客前發現缺陷. before the product reaches the customer!detection can also assess how effectively a ty

46、pe 1 control can prevent failure，第1類控制可以預防失效的有效程度11. Detecting failure探測度11. Detecting failure探測度Detection Rating (D)，探測度評分(D)9-10very remote chance this control will detect the cause or failure查明失效或其緣由的能夠性極小7-8remote chance ，能夠性很小5-6moderate to low chance ，能夠性不大2-4moderately to very high chance ，能夠

47、性較大 1almost certainly (if the part passes this test, its OK to ship)幾乎都可以查到(如能經過這項檢測，那么可放心發貨)Detection (D)CriteriaInspectionTypesSuggested Range of Detection MethodsABCAlmost ImpossibleAbsolute certainty of non-detection.XCannot detect or is not checked.Very RemoteControls will probably not detect.X

48、Control is achieved with indirect or random checks only.RemoteControls have 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 c

49、harting methods, such as SPC Statistical Process Control.ModerateControls 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 operation

50、s, OR gauging performed on setup and first-piece check (for set-up causes 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.Control

51、s have a good chance to detect.XXVery HighControls almost certain to detect.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 d