【Dell的FMEA教材失效模式影响分析】.doc

Failure Mode Effects Analysis失效模式影响分析Objectives课程目标By the end of the training, you will be able to:在本堂课程结束时, 您将能够:1. Compare and contrast the different types of failure mode effects analysis (FMEA).比较与对照不同类别的失效模式影响分析 (FMEA).2. Characterize the differences in questions asked in completing each type of FMEA.区分在完成不同类别的FMEA过程中所提出问题的特性.3. Define design FMEA and process FMEA.定义设计FMEA与流程FMEA.4. Describe how to apply FMEA to a process map.了解如何将FMEA运用于流程图.5. List the steps and components used in building an FMEA.将建立FMEA的步骤与要件列出.6. Demonstrate how to assess level of risk.展示如何评估风险等级.7. Prioritize risk assessment to drive corrective actions.排定风险评估优先级以推动矫正措施.FEMA and What is it?什么是失效模式影响分析FMEACould these have been avoided? The Bhopal tragedy The Valujet air crash The contamination of meat at Hudson Foods The Y2K problem下列事件原本是否可以避免呢? 印度波布尔化工厂毒气外泄惨剧 美国Valujet 航空公司坠机意外 美国Hudson食品公司肉品污染事件 千禧虫问题 What is FMEA?什么是失效模式影响分析 Disciplined approach to studying failures in- Product- System- Process- Service- Plus causes and effects有系统的研究下列各种失效- 产品- 系统- 流程- 服务- 原因与结果 Method that quantifies level of risk用量化评估风险等级的一种方法. Requirement of QS9000QS9000 品管系统要求条件之一. Tool to use on new or existing products, processes, services, etc.用于新的或现有的产品, 流程, 服务, 等等的工具. When FMEAs Should Be Conducted何时该做FMEALife Cycle Cost生命週期成本Stages in Product/Service Life Cycle產品/服務生命週期之各個階段 FMEA ExerciseFMEA练习FMEA Exercise 1FMEA练习一Consider the pager as a communication device. Answer the following questions:将呼叫器当做一个通讯工具. 回答下列问题:1. Identify the most serious failure that can occur with a pager.列出呼叫器可能发生最严重的失效状况 (故障). _2. What could be the “worst case” effect of this failure?这个失效状况所能导致的最糟结果是什么?_3. Identify 5 causes that lead to such failure, and rank in order of priority for corrective action.列出五个导致这个失效状况的原因, 并将它们矫正措施的优先等级列出.Cause原因Rank等级 FMEA Exercise 1, ContinuedFMEA练习一, 续前页Points to consider: What was the basis for allotting the ranks you did? How sure did you feel about what you were doing? Do you think your ranking will agree with most other people in the class? Why? Would a team effort be better or worse?考虑以下各点: 您分配优先等级的参考依据是什么? 您对您的结论有多大的信心? 您认为这个班里大部份的学员会同意您的评比等级吗? 为什么? 小组合作的结果会更好或更差? Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页Probability of Occurrence Cause发生机率 原因Very rare, maybe once in 10 yrs., or 1 ppb1非常罕见, 每年才可能发生一次, 或小于十亿分之一Rare, maybe once in 5 yrs., or X00 ppb2罕见, 每五年才可能发生一次, 或大约为十亿分之数百Could occur somewhat frequently, more than once / 2 yrs., or 100 ppm3发生频率略高于每两年一次, 或小于百万分之一百Could occur 1 to 3 times / yr or between 100 and 1000 ppm4每年发生一至三次, 或介于百万分之一百至百万分之一干Definitely more than one occurrence per quarter, or above 1000 ppm5发生频率多于每季一次, 或高于百万分之一千Severity Effect严重性 影响Minor inconvenience in personal / work life1对个人生活与工作稍有不便Noticeable impact to work schedule / personal plans2对个人与工作计划稍有影响Affects relationships with boss / family members3对上司 / 家人之间的关系有影响Loss of revenue, relationships, and or reputation4对收入, 关系, 或名誉有损失Could result in injury, / other safety issues 5导致受伤或其它安全事故Detection Failure Mode (or Cause)侦测能力 失效模式 (或原因)Failure or its cause is readily or self evident1失效本身或其原因显而易见或自行彰显Manual inspection or test can easily detect failure / cause2人工检验或测试可以轻易侦测到失效或其原因Failure is hard to detect, special instruments or training req.3失效不易侦测, 必须要有特殊仪器或训练Failure detection will destroy the unit4失效侦测过程会损毁产品Failure can slip by unnoticed5无法侦测到失效Complete the following FMEA Rating Worksheet for the problem in Exercise 1.将练习一的问题排定FEMA优先等级并填入下表.Product or feature产品或特性Failure mode失效模式Effect影响SCause原因OCurrent controls现行管制DRPN风险系数Rank等级Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页 Common types of FMEAFMEA的一般类型 Design/Product Focus on product, system, sub-system, or component part设计/产品 重点在产品, 系统, 次系统, 或零附件. Process Focus process. Output usually a product流程 重点在流程本身. 其输出通常为产品. Service Focus on process, but output is service服务 重点在流程. 但其输出为服务.Design/Product FMEA设计/产品FMEABenefits: Increases robustness of designs Identifies failure modes Enables priority setting for corrective action Supports failure discussion between different groups Provides a framework for continuous improvement of designs Identifies often missed failure modes when used at systems levelCustomers: End user, manufacturing, assembly, service and 好处: 更完善的产品设计 找出失效模式 得以设定矫正措施的优先级 支持不同工作小组之间的失效案例讨论 提供设计持续改善的工作架构 找出在系统阶层经常遗漏的失效模式客户: 最终用户, 制造, 组装, 服务, 与Process FMEA流程FMEABenefits: Increases robustness of process Identifies high risk process steps Identifies process variables controls Supports failure discussion between different groups Documents results of process Provides framework for continuous improvement of processes Customers: End user, down stream manufacturing / assembly processes, service operations and好处: 更完善的流程设定 找出高风险的流程步骤 找出流程变量的控制办法 支持不同工作小组之间的失效案例讨论 经由纸上作业制订流程 提供流程持续改善的工作架构 客户: 最终用户, 下游制造, 组装流程, 服务作业, 与Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页 Service FMEA服务FMEABenefits: Reduces probability of service not meeting expectations Identifies failure modes Enables prioritization for corrective action Pin points high risk steps in service process Identifies highest value control stepsCustomers: End user, downstream process owners, and .好处: 降低服务不良的机率 找出失效模式 得以设定矫正措施的优先级 精确指出在服务流程中的高风险步骤 找出最高价值的管制步骤客户: 最终用户, 下游流程负责人, 与 Define the scope for the FMEA定义FMEA的范围Step 1Define the boundaries within which the product, process, or service will be studied, identifying the operating assumptions, current conditions, and Constraints if any.步骤一定义要所要研究的产品, 流程, 或服务的研究界限, 确定作业假设条件, 目前状况, 以及可能的限制.The Influence of Level不同阶层的影响 RadiatorPump, V Belt Diaphragm, Bi Metal Spring Safety, LubricationEngine, Braking, Exhaust Trans., Cooling ThermostatExample of a ProductLevel阶层Focus重点Failure Mode失效模式Cause原因Effect影响System系统Car轿车Overheating引擎过热Cooling system failure冷却系统失效Stranded on the road在途中抛锚Sub-system次系统Cooling system冷却系统Inadequate coolant flow冷却剂循环不当Thermostat stuck closed澎胀阀死锁Car overheating轿车引擎过热Sub-assembly次组合Thermostat澎胀阀Stuck closed死锁Bi-metal spring broken铋金属弹簧断裂Inadequate coolant flow冷却剂循环不当Component零件Bi-metal spring铋金属弹簧Broken断裂Fatigue金属疲劳Thermostat stuck closed澎胀阀死锁 Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页Example of a Process流程举例CompanyPlant 4Plant 3Plant 2Plant 1PCB LinePower suppliesFHP MotorsOp 250Op 20Op 10FMEA can be conducted at any of these levels; it all depends on your objective依据您的目的, FMEA可应用于以上任何一个阶层.Op250Op 240210Op 10Op 120Op250OpA20OpA10Level阶层Focus重点Failure Mode失效模式Cause原因Effect影响System系统Factory (Plant 2)工厂 (二厂)Late delivers to customer交货延迟Low FPY on Line 2第二线直通率过低Lost business损失订单Sub-system次系统Line 2 (power Supplies)第二线 (电源供应器)Low FPY直通率过低High rework at / after testing测试后重工率太高Late deliveries交货延迟Operation作业站Testing Op 210第210测试站High rework重工率太高Testing results inconsistent测试结果不稳定Low FPY直通率过低Important: You must be able to see a cascading of failure modes, causes, and effects.重要提示: 您必需要能看出失效模式, 原因, 和影响的系列关联.Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页 Define the scope for the FMEA, cont.定义FMEA的范围, 续前页Step 2Identify team members, customer, and knowledge expert/sInvolve the customer in the process.步骤二确定小组成员, 客户, 与专家.邀请客户参与作业Step 3Develop roles and responsibilities for team membersLeverage the strengths of each team member步骤三指派小组成员职掌充分运用各小组成员之长处Step 4Study the product / Process / ServiceAll team members work to familiarize themselves with the product, process, or service步骤四研究产品 / 流程 / 服务各小组成员致力于熟习产品, 流程, 或服务Step 5Develop rating scales for Severity, Occurrence, and Detection步骤五建立严重性, 发生机率, 与侦测能力的评比等级Quantifying failure modes, effects and causes量化失效模式, 影响, 与原因CausesFailure Modes*Effects原因失效模式影響OccurrenceDetectionSeverity發生機率偵測能力嚴重性How severe?有多嚴重?Who has the most info?誰有較多的資訊?How easy to detect with current controls?現有的偵測能力有多好?Who has the most info?誰有較多的資訊?If prevented will effects be eliminated?預防措施是否可以消除影響?How frequent?多頻繁?Who has the most info?誰有較多的資訊?If eliminated, will failure be avoided?如果消除了發生機率, 失效是否可以避免?Failure Mode Effects AnalysisFMEA分析, 续前页, Rating ScalesFMEA分析, 评比等级来源于 中国最大的资料库下载Rating scales评比等级Example from Design FMEA设计FMEA举例Severity 严重性Occurrence 发生机率Detection 侦测能力Effect 影响Cause 原因Failure mode or cause 失效模式或原因 1-No effect无影响2-Minor effect - fit/cosmetics轻微影响 配合 / 外观3-Major effect - fit/cosmetics严重影响 配合 / 外观4-Minor reduction in Function功能稍受影响5-Customer dissatisfied客户不满意6-Major reduction in function功能大受影响7-Totally dysfunctional功能完全不正常8-Presents minor hazard形成轻微危险9-Presents injury hazard造成受伤危险10-Fatal if used造成致命危险1-Remote chance,=200 for each failure mode:以RPN = 200作為失效模式門檻的舉例FMEA; Step by StepFMEA; 逐步展開Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页来源于 中国最大的资料库下载 Define the scope for the FMEA, cont.定义FMEA的范围, 续前页Step 11Prioritize based on RPN and severity, or as requiredby customer步骤十一依据风险等级数和严重性, 或客户要求排定优先次序11Prioritize based on RPN and severity, or as required by customerArrive at the order in which you will start addressing the failure modes and causes for corrective action. Although RPN and severity based prioritization seems the most logical, your decision to proceed must be made with customer input. This step is easily accomplished by sorting the data, in descending order. You can do this within each failure mode to maintain data integrity.Documentation on work sheet is important to ensure the whole team is in sync.依據風險等級數和嚴重性, 或客戶要求排定優先次序這個優先次序是您將用以處理與矯正失效模式及原因. 雖然依據RPN與嚴重性所訂出的優先次序看來是最合理的, 但您最後的決定必須要納入客戶的意見.這個步驟可以很容易的藉由將數據以由大到小的順序排列出來而完成. 您可以將這個步驟分別運用於每一個失效模式之中以保持資料的完整性.將作業過程與結果記錄於工作表上以確保整個小組的步調一致是很重要的.FMEA; Step by StepFMEA; 逐步展開Failure Mode Effects Analysis, ContinuedFMEA分析, 续前页Define the scope for the FMEA, cont.定义FMEA的范围, 续前页Step 12Identify corrective action步骤十二决定矫正措施12Identify Corrective ActionIn this step you identify the corrective actions needed to eliminate / control the causes, and reduce the risk level to or below the agreed upon threshold.There will be times when you cannot work on the root cause; in such cases the best course of action will be via addition of controls / adequate warning devices / mechanisms of impending failure. Re-evaluate the ratings for S, O, and D, followed by RPN calculation.Discussion with the customer is important again since the corrective actions will impact them. Knowledge experts may also provide valuable input as to what kinds of corrective action will be best suited for the given cause / failure mode. Finally, from all possible corrective actions, the team may choose one based on cost / benefit analysis, speed of implementation, and the new level of risk. 決定矯正措施本步驟針對符合先前所訂定門檻條件之項目製定矯正措施以消除或控制失效原因, 並降低風險程度.有時您會無法找出失效的根本原因, 在這個時候最好的辦法就是對即將發生的失效追加管制方法, 設立適當的警告設置 / 機制. 重新評估 S, O, 和 D, 並重新計算