Modelling the Influence of Maintenance Actions

An operating system is observed to undergo failures. On failure, one of three actions was taken: failures were minimally repaired, given a minor repair or given a major repair. Furthermore, periodically the machine was stopped for either minor maintenance action or major maintenance action. Either on failure or maintenance stoppage, both minor and major repairs are assumed to impact the failure intensity. The issue in this research is to identify the virtual aging process associated with repairs. A series of models appropriate for such an operating/maintenance environment are developed and estimated in order to identify the most appropriate statistical structure. Field data from an industrial setting are used to fit the models.