Optimal preventive maintenance policies for a shock model with given damage level

Purpose - This paper considers and discusses analytically the optimal preventive maintenance (PM) policies of aged plants such as fossil-fired power plants. Design/methodology/approach - Shocks are assumed to occur at a nonhomogeneous Poisson process and the total damage due to each shock is additive. The system undergoes the PM at a certain time or the total damage exceeds a managerial level. The expected cost rate until PM is derived and optimal policies which minimizes it are discussed. Findings - There exists a unique optimal time (T*) or managerial level (k*) which minimizes the expected cost rate. But there does not exist a positive pair (T*, k*), simultaneously. Research limitations/implications - The damage occurrence distribution is assumed to be nonhomogeneous Poisson one. Practical implications - Useful methods to consider the optimal PM policies for power plant engineers. Originality/value - This paper contributes to users of aged power plants economically and practically.