Hazard analysis based on human-machine-environment coupling

The concept "Human (H)-Machine (M)-Environment (E) coupling" is put forward, and the connotative meaning and representation of the hazards owning to coupling is represented. Based on Process Breakdown Structure (PBS), the method characterizing H-M-E coupling in operational process is put forward, and a multi-view model for integrated analysis is established. The model describes an operational process from 9 perspectives including H, M, E, H-H, M-M, H-M, M-H, E-H, E-M. It provides pragmatic technical means to explore interaction or interconnection among factors of human, machine and environment. Based on engineering practice, the comprehensive hazard analysis method is built. It aids to discover the modes and causes of hazards resulted from the complex H-M-E coupling, and determine the “trigger” mechanism in occurrence of H-M-E hazards. The method provides integrated technical support for subsequent risk assessment. Finally, by means of the methods and models above, hazard analysis based on H-M-E coupling was implemented on a case of approaching process of airliner. The analysis did verify the engineering feasibility and effectiveness of the above-mentioned methods. Moreover, analysis results and findings did identify hazards due to H-M-E coupling and combinations of hazard causes during flight phase of airliner, which is some difficult for methods regardless of interrelation among system elements. So that defects in design were mo dified in time to ensure human, machine and environment in the best state and to improve the inherent safety of system. With the coupling model, some hazards which are hard to identify with common methods of system safety analysis could be recognized, and the relationship from hazard causes to mishaps is expressed more clearly. Moreover, its practice proves its engineering feasibility.