Optimal Maintenance Policies for a System With Multiechelon Risks

Aged fossil-fired power plants are on the great increase in Japan, and the importance of preventive maintenance (PM) increases for their steady operations. A plant consists of a wide variety of mechanical and electrical components. Various kinds of severe failures inherent in these components and their occurrence probabilities are different. A system fails when the total suffered damage exceeds a peculiar level, i.e., these components have their peculiar damage levels. The PM plan should be established, considering such levels of plant components. In this paper, kinds of peculiar cumulative damage levels are considered, and a system fails when the total damage exceeds these damage levels. The PM is performed when the total damage exceeds the managerial one . The expected cost per unit time between maintenances is secured, and the optimal managerial level which minimizes it is analytically discussed.