Repairable System Reliability: Recent Developments in CBM Optimization

This paper presents some developed and implemented theory which can be applied to optimization of condition-based maintenance decisions within the context of physical asset management. We examine a replacement problem for a system subject to stochastic deterioration. In particular, the analysis of a preventive replacement policy of the control-limit type for a system subject to inspections at discrete points of time is presented. Cox’s Proportional Hazards Model with Weibull baseline hazard function and time dependent stochastic covariates, reflecting the item’s condition, is used to describe the hazard rate of the system. Statistical results are then blended with economic or performance considerations to establish long-run optimal maintenance strategies. The structure of the decision-making software EXAKTTM is presented, and recently added optimization and prognostic capabilities are described.