A sequential condition-based repair/replacement policy with non-periodic inspections for a system subject to continuous wear

This paper studies a condition-based maintenance policy for a repairable system subject to a continuous-state gradual deterioration monitored by sequential non-periodic inspections. The system can be maintained using different maintenance operations (partial repair, as good as new replacement) with different effects (on the system state), costs and durations. A parametric decision framework (multi-threshold policy) is proposed to choose sequentially the best maintenance actions and to schedule the future inspections, using the on-line monitoring information on the system deterioration level gained from the current inspection. Taking advantage of the semi-regenerative (or Markov renewal) properties of the maintained system state, we construct a stochastic model of the time behaviour of the maintained system at steady state. This stochastic model allows to evaluate several performance criteria for the maintenance policy such as the long-run system availability and the long-run expected maintenance cost. Numerical experiments illustrate the behaviour of the proposed condition-based maintenance policy. Copyright (C) 2003 John Wiley Sons, Ltd.