Reliability and hybrid maintenance modeling for competing failure systems with multistage periods

This paper deals with the reliability and hybrid maintenance models for systems which are subjected to competing and dependent failures due to degradation and external shocks. System studied here are with multistage periods, standby stage, working stage and the stop stage, which makes it different with previous literatures. The characters of degradation and external shocks vary with different periods and this also makes the proposed reliability model more challenging and more consistent with the engineering reality. Besides, a hybrid maintenance policy combined by age-based preventive maintenance and condition-based maintenance is studied by minimizing the average long-run maintenance cost. The optimal age-based preventive interval and the condition-based threshold are both calculated to manage the minimum maintenance cost. A numerical case demonstrates the availability and general applicability of proposed reliability and maintenance models at the end of this paper.