Design And Application Of The Dynamic Risk Analysis Method Based On The Failure Casual Model

In safety-critical system, the risk analysis is an important evaluation criterion for system safety. Risks are generally related to the frequency and losses of an accident. Accidents are the result of equipment failure, human error and improper organizational management. In this thesis, a dynamic risk analysis method based on technology, equipment, human factors and organizational management was put forward and a dynamic risk analysis model was constructed.The main work of this thesis is as follows:Firstly, the core concerns of the risk analysis theory in three generations were summarized; the definition of risk and the research status of risk analysis in various fields at home and abroad were introduced. Meanwhile, the common risk analysis methods in the safety-critical system were reviewed.Secondly, from the technology, equipment, human factors and organizational management’s angle, the method of dynamic risk analysis was proposed and the framework of dynamic risk analysis model was constructed by combining the characteristics of System Dynamics model, Petri Net model and Agent Base model. The dynamic risk analysis model covered safety-critical system in four aspects as modeling, verification, simulation, and evaluation analysis. The Monte Carlo experiment was introduced for performing the analog simulation of random dynamic. The requirements of the users were satisfied step by step through analog simulations, parameter optimization experiments, parameter sensitivity analysis experiments and parameter contrast experiments.In addition, on the AnyLogic platform, with the help of its extensive development tools, the Extend Petri Nets library and Human Factors library for the model were developed, and the unity of dynamic risk analysis modeling platform was completed. Also, the real uncertainty system simulation experiments were realized by combining with the Monte Carlo experiment method.Finally, a safety-critical system was considered as an example in railway system, four aspects of the management subsystem, human resource subsystem, maintenance subsystem and operation scenario are respectively modeled to analyze, in which an entire process of dynamic risk analysis theory from modeling to application was specified and the effectiveness of the dynamic analysis method was verified.