Simulation Model for the Maintenance of a Deteriorating Component System

The model finds the optimal time-independent component replacement policy for a system composed of components subject to probabilistic deterioration. According to this policy the system is reviewed periodically and components are replaced such that the system will operate at minimum expected cost. The final policy is easy to implement since decisions depend only upon the observed state of the system; hence, no component monitoring is required. Both the cost of operating the system in a degraded state and component replacement costs are considered. The model assumes that all past decisions affect the current system state as well as the system improvement cost. All time-independent policies are simulated and the one yielding the lowest expected cost is chosen. This paper presents the general mathematical development of the model with a description of the simulation procedure and a simple example of a six-component system.