【正文】 t leave the space on the form blank. Write None 不要在表上留下空格不填。 覺察產(chǎn)生失效的原因 ； (3) Those that detect the failure mode(s) 檢測失效模式 48 FMEA Detection Rating (D): 探測度評分 910 Remote chance of detecting failure 察明失效的可能性極小 78 Very low chance， 可能性很小 56 Low to moderate chance， 可能性不大 24 Good chance， 可能性較大 1 Will almost certainly detect failure (If it passes this, it will not fail) 失效幾乎都可以被査到 (如果通過這樣的 檢查就不會有失效 ) 49 FMEA ? To reduce severity design change to control the effect 降低嚴重度 – 通過設(shè)計更改來控制後果 ? To reduce occurrence design change to control the cause 減少發(fā)生頻度 通過設(shè)計更改來控制原因 ? To improve detection improved testing or simulation methods 增強探測度 – 改進測試和模擬方法 ? Special Attention if Severity = 9 or 10 當嚴重度為 9或 10時要特別注意 50 FMEA General Steps in the PFMEA/一般步驟 ? Select process FMEA team 組建過程 FMEA小組 ? Develop a Process Map and identify all process steps 做一個流程圖確定過程的所有步驟 ? List all the Key Process Outputs to satisfy internal and external customer requirement 列出所有的滿足內(nèi)部和外部客戶要求的關(guān)鍵過程輸出 ? For each process step, list Key Process Input Variables 列出每一步的關(guān)鍵過程輸入變量 ? For the Process Define CE matrix relating Key Outputs to Key Process Input Variable 用因果圖分析關(guān)鍵過程輸入和關(guān)鍵輸出的聯(lián)繫 ? Rank the KPIVs according to importance 根據(jù)重要程度給關(guān)鍵過程輸入變量分級 ? Start the process FMEA 開始做過程 FMEA 51 FMEA General Steps in the PFMEA/一般步驟 ? For each process input, list ways that it can vary (failure Modes) and identify associated effects 對每一個過程的輸入 ,列出其可能的變化和相應(yīng)的後果 ? List all Causes for each Failure Mode 列出失效模式的所有原因 ? List the current Controls for each cause 列出每個原因的現(xiàn)有控制手段 ? Assign Severity, Occurrence, and Detection ratings to each cause 給每個原因的嚴重度 ,頻度 ,可探測度評分 ? Calculate the RPN for each potential Failure Mode scenario 計算每個潛在失效模式的風險序數(shù) ? Determine remended actions to reduce High RPNs 提出降低風險序數(shù)的措施 ? Take appropriate actions 採取適當?shù)拇胧? ? Recalculate RPNs 重新計算風險序數(shù) 52 FMEA ? Use the Process Flow Diagram format 適用流程圖的格式 – Identifies fabricate, move, store and inspect operations 識別四種作業(yè)類型 ,製造 ,移動 ,儲存 ,檢驗 – Identifies Key Characteristics 識別關(guān)鍵特性 ? A function is what the operation does 功能系指該操作所起的作用 ? State the function as /說明功能為 ： Verb + Object + Qualifier 動詞 +賓語 +修飾詞 Mold part /成型零件 Crimp terminal onto cable /電線上壓接端子 Form bend in part /零件彎曲成形 53 FMEA ? A customer want or desire 顧客的希望或要求 ? Could seriously affect customer perception 有可能嚴重影響顧客的看法 ? Could lead to a customer plaint 有可能導(dǎo)致顧客投訴 ? A defect, flaw, or other unsatisfactory condition in the product that occurs when the process fails to meet the process requirements 由於過程未達到要求而導(dǎo)致的産品缺陷、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)在産品上 54 FMEA ? Typical Failure Modes /幾種典型失效模式 ? Diameter out of spec. /直徑超差 ? Missing seal /漏裝密封墊 ? Cut strands /切破線皮 ? Missoriented part /部件方向錯 ? Insufficient solder /焊劑不足 ? Too much solder /焊劑過量 ? NFO, Flash /未充滿 ,飛邊 ? The ramifications of failure/後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 government regulation /政府法規(guī) ? The next process step /下工序 55 FMEA ? Customer plaints are a useful source of information 顧客抱怨是非常有用的資訊來源 ? An effect can be /後果可能是 ? Complete loss of function /功能完全喪失 ? Degradation of performance or quality /質(zhì)量或性能下降 ? Damage of process equipment /設(shè)備受損 ? Injury to an operator /員工受傷 ? Shutdown of an assembly line /停線 ? Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer /失效的後果 通常表現(xiàn)爲從對顧客的直接影響到最終影響等一系列連鎖反應(yīng) ? It is remended that these chains be developed for each failure mode and recorded on the FMEA form /建議針對每一種失效模式找出這些連鎖反應(yīng)，並記錄在 FMEA表上 56 FMEA ? A cause of failure is how the failure can occur in the process 失效原因就是過程爲何會失效 ? Should be written in terms of something in the process that can be corrected and controlled 應(yīng)表述爲 可糾正或可控制 的因素 ? Consider human error, wearout of tools, ambient conditions, and interactions of factors 如人的過失，工裝磨損、環(huán)境條件以及因素間的相互作用 57 FMEA Effects on the process /對過程的影響 ? 910 May endanger machine or operator / 可能導(dǎo)致設(shè)備或人員受損 ? 68 Scrap /報廢 ? 45 Sort and rework /篩選和返工 ? 23 Rework online /在線返工 ? 1 No effect /無影響 Consider Also the Effects on the Customer 還要考慮對顧客的影響 58 FMEA ? Use historical data (as a baseline) /利用歷史資料 ? Take improvements into account 考慮改進 910 Failure almost inevitable /失效幾乎不可避免 78 Similar processes that have often failed in the past 以前類似過程常常失效 46 Similar processes that have occasional failures 類似過程偶爾失效 13 Similar processes that have experienced isolated failures /類似過程僅有過個別失效 59 FMEA CauseandEffect Chain 因果鏈 Tool Is Worn 夾具磨損 Tool Not Replaced 夾具未更換 Lack of Maintenance Procedure/沒有保養(yǎng)程序 Clamp Cracks at Bend夾子在彎曲處裂紋 Bundle Falls Out 線束散開 Rattling Noise 卡嗒聲噪音 CAUSE chain 原因鏈 EFFECT chain 後果鏈 Radius Out Of Spec 半徑超差 60 FMEA Crossed Wire 交叉的電線 No Function 沒有 功能 Causes Tree/原