Abstract: Common mode analysis and zone safety analysis need to be conducted to the safety critical avionics system in order to form new separation requirements.As the avionics system is becoming more and more integrated,the traditional common mode analysis and zone safety analysis methods can’t ensure the completeness of the separation requirements as they mainly rely on how well the analyzers understand the system.Meanwhile,the requirements of the system are hard to be traced due to the differences between the understanding of the safety analyzers to the system and that of the system designers,especially when the design changes frequently,safety analysis results are always inaccurate and inconsistent.Aiming at the above problems,a safety analysis tool based on avionics system architecture model was designed and implemented.Fault tree auto-modeling was conducted through tracing the data signal path in physical architecture.Then common mode analysis and zone safety analysis were conducted based on the generated fault tree,getting a common mode checklist and some zone separation requirements.The results of the case study on one cockpit display system indicate that the tool is able to conduct auto fault tree modeling based on the avionics system architecture model described in SysML,and also can mark the components need to be isolated,ensuring the completeness of the results of common mode analysis and zone safety analysis.

Key words: Avionics system architecture model,SysML,Common mode analysis,Zone safety analysis,Fault tree modeling