On preventive maintenance of systems with lifetimes dependent on a random shock process

We consider preventive maintenance (age replacement) of items operating in a random environment modeled by a Poisson process of shocks. An item is replaced either on failure or on the predetermined replacement time, whichever comes first. Each shock in our stochastic model has a double effect. On one hand, it acts directly on the failure rate of an item, which results in the corresponding stochastic failure rate process. On the other hand, each shock causes additional 'damage', which can be attributed, e.g., to a short drop in the output of an item. The corresponding optimization problem is considered and illustrated by detailed numerical examples. - Highlights: • We consider preventive maintenance of items under a Poisson random shock process. • This paper deals with a double effect of shocks. • This paper presents an analytical solution for the long-run cost rate. • This paper presents examples and discussion on optimal preventive maintenance time.