A System Safety Modeling and Assessment Method Based on ETFPGs

This paper proposes a system safety modeling and assessment method based on failure propagation and evidence uncertainty quantification theory. This method first defines evidential belief time failure propagation graphs (ETFPGs), and a 6-tuple model of system failure propagation is proposed to describe the process of system failure propagation. Then, the uncertainty of failure events is quantified by using evidence theory, and the Belief Interval (BI) of the final hazard occurrence as well as the failure propagation time are calculated. Based on the ETFPG, the general process of complex system safety modeling and assessment is obtained. This method can evaluate the safety of the system with limited sample and information. A case study is carried out in this paper to illustrate the engineering adaptability of this method.