失效模式與效應分析的評價方法

摘要

現行的失效模式及效應分析，絕大部分是以效用函數來評價失效風險的大小來做爲問題改善順序的依據，尤其傳統上是採行頗受爭議的風險優先數，其評價方式，是將各項因子由非明確數値轉換成分數，再經由相乘運算得出，在決策上又忽略各因子之相對重要性。因此，本研究擬利用模糊理論(Fuzzy Theory) 的方法直接評估各項因子的等級，以解決轉換之質疑，同時透過灰色系統理論(Grey System Theory) 之灰色關聯分析，以解決傳統方法利用因子相乘及決策各因子無相對權重的爭議。經過本研究之實例驗證，同時利用模糊理論與灰色理論來處理FMEA的改善決策、確實比傳統的失效模式及效應分析更具方便性與公正性。

Abstract

The quality improvement priority in early stage of product design and process planing for manufacturing industry can be determined using Failure Mode and Effects Analysis, namely, FMEA Technique. It can discover potential design or process problems and thus, increase product reliability. In order to fulfill the high quality requirements & reduce the nonconforming rate in production, the implementation of process FMEA is highly needed. The existing FMEA technique uses utility function to evaluate the risk priority for correcting the potential problems. It transfers the uncertain linguistic assessment into a crisp number, and then calculates the multiplication of factor, not only the transformation is questionable, but also the relative importance of factors is neglected. Therefore, in this research, we use fuzzy method to solve transformation problem & grey theory to include the relative weighting coefficients. The comparison results indicate that concurrent application of fuzzy method & grey theory can eliminate all problems incurred by traditional FMEA technique.

關鍵詞:

• 失效模式與效應分析
• 模糊理論
• 灰色理論

Keywords:

• FMEA
• Fuzzy Method
• Grey Theory