State-based safety analysis method for dynamic evaluation of failure effect

System state that represents a combined influence of internal and external system parameters on the overall failure effect plays a significant role in failure effect analysis. The traditional safety analysis methods can hardly evaluate the overall failure impact due to the dynamic failure behaviors in diverse system interaction situations. To overcome this problem, this paper proposes a state-based safety analysis method for dynamic evaluation of the failure effect combining the situation factor. First, a hierarchical modeling framework that includes functional logic, physical architecture, and the failure mode is constructed, and then the cross-linking relationships between items are characterized by the state machines. Particularly, the event transmission mechanism and the global attribute updating mechanism are designed to realize the state synchronization of various systems, thus enabling the global propagation of failure. The feasibility of the proposed method is verified by simulations. The Enterprise Architect platform is used to model the aircraft integrated surveillance system and analyze the effects of different failure modes in typical situations. The proposed method complements the failure effect evaluation accuracy considering the dynamic interaction situations, thus realizing the global perception of the safety state, enhancing the dynamics and integrity of the failure effect analysis process. © 2020, The Author(s).