Basic Event Probability Determination and Risk Assessment Based on Cause - Consequence Analysis Method

Abstract

Abstract Reasonable determination of the probability of occurrence of basic events is the basis of scientific risk assessment. The cause-consequence analysis method developed from the theory of system reliability is an effective method to determine the probability of basic events. Taking the motor overheating event as an example, based on the reliability theory of human and machine, from the perspective of “safety control system for the occurrence and development of motor overheating fire event”, the “motor overheating safety control system” is determined as the target system. Through the investigation and analysis of the functional composition of the target system, the reliability block diagram of the target system is obtained. And the logical relationship of link events is determined. According to the reliability theory, the probability of each basic event is investigated and calculated. Finally, the risk assessment diagram of motor overheating is obtained. The results show that the equal risk line in logarithmic coordinate is a straight line. This line is the critical line of acceptable risk. This research solves the problems of the current cause effect analysis, such as the unclear choice of the target system, the confusion of the logical relationship between the link events and the unclear source of the basic data. The study of quantitative analysis details based on reliability theory improves the operability and application effect of cause consequence analysis method, which is helpful for its popularization and application.