An Integrated Reliability and Testability Modelling and Simulation Method Based on Extended GSPN Considering Sequential Faults

Reliability and testability are critical in modern industrial systems for ensuring high operational efficiency and minimising lifecycle costs. However, existing research often neglects their intrinsic coupling, treating them as separate entities, and fails to address sequential fault scenarios under prolonged operation. To bridge these gaps, this paper proposes an integrated reliability and testability modelling and simulation method based on an extended Generalised Stochastic Petri Net (EGSPN). The EGSPN introduces novel reliability elements and testability elements to holistically capture system failure and diagnostic behaviours. In addition, a multiple mission simulation method has been developed, which integrates fault propagation analysis, fault sampling, sequential fault diagnosis, mission abort and maintenance activities to simulate the long-term operation of a system. Furthermore, new testability metrics, including dynamic detection rate and dynamic isolation rate, are defined to evaluate diagnostic performance and identify system deficiencies under sequential fault conditions. Finally, a case study validates the effectiveness of the proposed method in assessing operational reliability and testability.