The interplay between deployment and optimal maintenance intervals for complex multi-component systems

Instead of performing maintenance at fixed intervals, the operational efficiency of assets can be improved significantly by taking into account the variations in usage and operating environment of the asset. In that way, the traditional static maintenance policy is replaced by a dynamic maintenance policy. In the present work, this concept is demonstrated by modeling the failure behavior of a rather complex multi-component system, i.e. a navy frigate. For this system, several non-identical subsystems are included. Some of the systems are unique on board, while others have been made redundant, which means that the criticality of the subsystems to the mission capability of the frigate varies. Moreover, the variation in deployment of the frigate in terms of mission types and operating environments is translated into various usage profiles for the subsystems. Simulations are then performed to obtain the optimal maintenance policy in terms of interval length and preventive maintenance threshold, given certain requirements for the deployability of the frigate in a certain period. Moreover, the sensitivity of the results for different subsystem initial service life times and variations in usage profile are investigated. The results show a clear dependence of the optimal interval on the mission program of the frigate and the subsystem failure behavior