An optimal maintenance policy for a system under periodic overhaul

A preventive maintenance policy with minimal repair at failure, periodic overhaul, and replacement is considered. A model describing the effect of overhaul is proposed and the expected cost rate is obtained under negligible or nonnegligible maintenance time. Based on this model, optimal number of overhauls and optimal interval between overhauls for minimizing the expected cost rate over infinite time horizon are determined. Under some mild conditions, a unique optimal maintenance policy exists and a closed-form expression for the optimal interval between overhauls is derived when the lifetime of the system follows Weibull distribution. Numerical studies are made.