Global Safety Management Method in Complex System Engineering

In System Engineering, one of the most critical process is the requirement management, particularly when it deals with the safety requirements. These one are non-functional requirements and are related to emergent properties, which come from the integration of the different system components. They must be identified as soon as possible, because they are guards to validate or not the system, which can require changes in system architecture. Moreover, they are formulated at system level and need to be declined at sub-system level. The objective of this paper is to propose a global safety management method based on well-known safety methods, in order to organize the different tasks to make the system safe. The method focuses mainly on the definition of the system safety requirements following risk and hazard analysis, and also on their declination according to a top-down approach. It is based on the famous Failure Mode, Effects, and Criticality Analysis (FMECA) and the use of Fault Trees and Event Trees.