Evaluate the orderings of risk for failure problems using a more general RPN methodology

Abstract

Risk assessment is a preventive analysis task of product design and the production planning process. The purpose is to assign limited resources to the most serious risk items and ensure that the product can achieve its designed functions under specific operating conditions. Most current failure mode and effects analysis (FMEA) methods use the risk priority number (RPN) value to evaluate the risk of failure. However, conventional RPN methodology has not considered the situation parameter and the relationship between components of a system with respect to its type (direct/indirect) and severity. Therefore, a more general and efficient algorithm to evaluate the risk of failure is needed. This paper proposes a more general RPN methodology, which combines the ordered weighted geometric averaging (OWGA) operator and the decision-making trial and evaluation laboratory (DEMATEL) approach for prioritization of failures in a product FMEA. A case of a thin film transistor liquid crystal display (TFT-LCD) product that has been drawn from a professional liquid crystal display manufacturer is presented to further illustrate the proposed approach. The result of the proposed method is compared with the listing approaches of risk assessment methods.