A System Safety Analysis Method Based on Multiple Category Hazard Factors

Safety issues of modern systems are becoming more and more serious. As safety is the emergence characteristic of system, there is necessary need for a safety analysis method which integrates kinds of hazard factors instead of current system safety analysis methods which usually study hazard information in single aspect. A system safety analysis method based on multiple category hazard factors is proposed in this paper. Firstly, the finite state machine is used to describe the system, and the trigger events are improved in time and signal representation. Then, the paper takes into account three kinds of hazard factors of the system which include hardware failure, software defect and improper control action. Finally, the paper uses Simulink/Stateflow to build and test the system to find hazard path in order to improve the system. As for the case study, the paper takes the aircraft flap/reverse-thrust system as an example; by analyzing the safety of the aircraft landing phase, the effectiveness of this method is verified.