Cascading Failure Analysis Method of Avionics Based on Operational Process State

In the context of functional integration of avionics, the complex operational process interaction has increased the complexity of the cascading failure analysis, which is significant to evaluate the overall safety status and design rationality. In order to achieve a dynamic and dimensional evaluation of cascading failures, this paper proposes a safety analysis method based on operational process state, with an operational process-orientated hierarchical system functional framework established by means of the state machine. Then the cascading failure causation dynamic search algorithms and the cascading failure causation tree structure are designed respectively to describe the failure propagation in combination. Consequently, cascading failure propagation paths and minimum cut sets are generated automatically based on the search result. By using the aircraft integrated surveillance system as a research object, the effect and cause of cascading failure assessed in various failure scenarios have validated the effectiveness of the proposed method, and the comparison against the existing model based safety analysis methods demonstrates the higher flexibility and efficiency of the proposed method. The proposed method enables the dynamic and overall assessment of system safety status concentrating on the cascading failure utilizing the operational process state, and further enhances the systemization and automation level of the safety evaluation process in the early development phase.