CTP版材製程失效風險之分析與評估

Analysis and Evaluation of the Manufacturing Failure Risks of CTP Plate

洪僖黛、梁紹任
H. T. Hung and S. R. Liang

正修科技大學 工業工程與管理系


摘要

CTP版材具有大幅縮短印前製程時間、材料使用的成本、以及提高印刷產能等特點,然而CTP版材製程的失效原因對CTP板材的品質具有決定性的影響。失效模式與效應分析(failure mode and effects analysis, FMEA)是一種預防性的風險管理技術,主要應用於分析與辨認產品設計系統的潛在失效模式,並根據風險優先指數(risk priority number, RPN)決定失效模式的改善順序,藉由適當的改善措施來降低失效率與提高可靠度;換言之,各個失效模式乃是以RPN為評比準則來進行排序,RPN數值越大表示失效風險越高,須優先立即改善。

本研究之主要目的是基於資料包絡分析法(data envelopment analysis, DEA)適用於決定多屬性決策分析問題(multiple attributes decision making, MADM)評估屬性權重之特性,將決定失效模式RPN的嚴重性、發生率、以及難檢度等風險因子視為評估屬性,在DEA的概念下,根據妥協規劃排序模式來構建CTP版材製程失效模式之評比指標RPN;除此之外,針對屬於不同風險分級的失效模式提出設定風險評估因子改進目標的方法,以達到實施FMEA降低CTP版材製程失效風險的目的。

關鍵字:CTP 版材、資料包絡分析法、失效模式與效應分析、風險優先指數。

ABSTRACT

CTP plate has some advantages for printing industry, e.g. shorter lead time for printing, less material cost, and higher production capacity. This study applies failure mode and effects analysis (FMEA) to explore the causes and the effects in manufacturing CTP plate. Failure mode and effects analysis (FMEA) is a preventive technology of risk management that is applied to analyze and to identify the potential failure modes in a system. The risk priorities of the failure modes are determined through the risk priority number (RPN), and appropriate improvement actions can be taken for decreasing the error. The RPN has the advantage of easy calculation and comparison, but it has been criticized to have some drawbacks. In order to improve the disadvantages, this study considers the three risk factors as the attributes of a multiple attributes decision making (MADM) problem and the RPN is the criterion for comparing different failure modes.

The characteristic of data envelopment analysis (DEA) is applied to determine the weights of the attributes. Based on the compromise programming ranking method in DEA, the evaluation and the ranking models of the RPN are proposed in this study. Moreover, by the RPN resulted from the proposed models, the method for setting the improvement target of the RPN is also developed. The results of ranking and classification of all failure modes could help the manufacturers to understand the causes and the effects in manufacturing CTP plate. Furthermore, they could decrease the failure risk in CTP manufacturing process and improve the quality of CTP plate.


Keywords: Computer-To-Plate(CTP) Plate; Data Envelopment Analysis; Failure Mode And Effects Analysis(FMEA); Risk Priority Number(RPN)