FMEA風險優先排序新方法

Abstract

目前大多數的風險評估方法使用失效模式和效應分析(Failure Mode and Effect Analysis，FMEA)方法來評估失效風險。傳統上，FMEA使用風險優先數（risk priority number，RPN）來評估失效風險，然而，傳統的RPN方法論有遺失專家們所提供的有價值資訊及未考慮順序權重的嚴重問題。因此，為修正傳統RPN方法用於評估失效風險的缺點，本研究提出兩種新穎方法，一是結合2-tuple及順序加權平均(OWA)運算子、另一是結合2-tuple及語意順序加權幾何平均(LOWGA)運算子，分別進行失效模式與效應分析。 本研究主要目的是有效地解決傳統RPN方法用於評估失效風險的缺點，以確保產品和製程之穩健性。並使用彩色超扭轉向列型液晶顯示器（color super twisted nematic，CSTN）產品設計及製造2個案例，進一步與本研究所提之方法與傳統RPN等方法比較。結果證明使用本研究所提之方法不會遺失任何專家所提供的有用資訊，且可提供更加精確及合理失效風險之排序。

Most current risk assessment methods use the failure mode and effects analysis (FMEA) approach to evaluate the risk of failure. Traditionally, FMEA uses the risk priority number (RPN) to evaluate the risk of failure. However, the RPN method has the serious problem, loses some message which the experts provide to have the valued message, and not consider the ordered weight. In order to improve the method of RPN evaluation, this study proposes two novel approaches. One is integrating 2-tuple and the ordered weighted averaging (OWA) operator in FMEA, and another is integrating 2-tuple and the linguistic ordered weighted geometric averaging (LOWGA) operator in FMEA. The main purpose of this study is to effectively resolve the main shortcomings of RPN evaluation to assure product and process robustness. Two cases of the Color Super Twisted Nematic (CSTN) product design and manufacturing that has been drawn from a professional LCD manufacturer in Taiwan to further illustrate the proposed approaches. After comparing the results that was obtained from the proposed methods with two other approaches, it was found that the proposed approaches do not lose of useful message provided by the experts. Moreover, the proposed methods provided a more accurate and reasonable ranking of the risk of failure.