Reduction and the Ordering of Basic Events in a Fault Tree Based on Rough Set Theory

摘要

The safe performance of manufacturing systems is, to a great extent, dependent upon the condition of their components. Closely monitoring the condition of the critical components and carrying out timely system diagnosis would help to reduce accidents frequency. Fault tree analysis (FTA) is a powerful tool for reliability studies and risk assessment. However, most research on FTA focuses on the generation of minimum cut sets and how to calculate the probability of main events. As a result, the issue concerning the ordering of basic events in a fault tree has been largely neglected. Efficiency and veracity of fault diagnosis are usually affected by logical ordering of basic events. In this paper, a novel approach based on rough set theory and a pairwise comparison table for reduction and ordering of basic events in fault tree is proposed. The details of the approach, together with the basic concepts of rough set theory, are presented. A case study is used to illustrate the application of the proposed approach. Results show that a reasonable ordering of basic events in a fault tree can be generated easily. With the ordering of basic events determined, a maintenance engineer in a manufacturing plant can then carry out fault diagnosis in an efficient and orderly manner, so as to prevent accidents.