Opportunity-based age replacement with different intensity rates
This article considers an opportunity-based age replacement model with different intensity rates. Most of the articles suppose that opportunities are generated according to a homogeneous Poisson process, where the intensity rate does not change with time. However, social, economical, and physical environments can change the intensity rate. We suppose the intensity rate changes at specific age. The occurrence of opportunities is independent to the failure of a component. Preventive replacement is carried out at the first opportunity after age.T. If the component breaks down then it is replaced immediately. We derive the expected cost per unit time for an infinite time horizon. An optimal policy to minimize the expected cost per unit time is derived. Finally, numerical examples are given. (C) 2003 Elsevier Ltd. All rights reserved.
intensity rate preventive replacement expected cost optimal policy unreliable systems