Modeling coupled effects of dynamic environments and zoned shocks on systems under dependent failure processes

In this paper, we focus on systems suffering from multiple dependent competing failure processes under coupled effects of zoned shocks and dynamic environments. A reliability and maintenance model is developed for a real-time inspected system subject to linear degradation and random shocks, in which the internal degradation rate and shock arrival rate are affected by a dynamic environment. Shocks are classified into four zones based on their magnitude, including the safety zone, probability damage zone, damage zone, and fatal zone. Explicit formulas for calculating reliability indexes of systems are derived, including the reliability function, availability function, and steady-state availability. Meanwhile, simulation algorithms for calculating these reliability indexes are provided based on the Monte Carlo method, which is beneficial to the verification of the analytical method. Finally, a case study of micro-engine systems is given to illustrate the proposed models and obtained results, exhibiting that zoned shocks and dynamic environments have a significant effect on system performance.