Improved zonal safety analysis method

Zonal safety analysis (ZSA) is important to system safety analysis, and it is especially required for the safety design of large airplanes now being developed in China. As the present ZSA method is not specific or definite enough to implement, an improved ZSA method was proposed in this paper. It first made definite how the results of FMEA and FMECA are input to ZSA in the traditional operation process, which made the method more practicable in the field of engineering. Moreover, hazard sources including both energy factors and failures of system hardware were analyzed, and hazard induced by coupling among those hazard factors in a complicated system was also analyzed. Thus a general set of hazard factors were established, which could be applied to analyze ZSA effect among the equipment inside a zone. Risk analysis was introduced to formulate rules of ZSA. The improved method could enhance safety of products, which was illustrated by an example of the undercarriage system on a certain airplane.