2022 年 8 巻 1 号 p. 40-50
Load-sharing is one way to improve the reliability of amulti-unit system. However, it also increases maintenance costs. Considerationof the trade-off between improving reliability and reducing maintenance costsis complicated by the fact that workload allocation can greatly affect the unitdeterioration rate. Decision making regarding maintenance and load-sharing musttherefore take into account the complex and dynamic interactions between unitdeterioration and workload allocation. This research considers condition-basedmaintenance for a system consisting of two identical units. An optimal joint maintenanceand load-sharing policy with flexible load-sharing is presented for two-unitdeteriorating systems under a constant total workload. The underlyingdeterioration process of the system, which depends on the workload allocation,is described by a continuous stochastic process. The deterioration state isobserved at the beginning of equally spaced time periods. The operator caneither continue operating the system for one more period with a certain loaddistribution ratio or initiate maintenance on either or both units on the basisof the deterioration state of the system. The decision-making problem isformulated as a Markov decision process that minimizes the total expected cost overan infinite horizon. The properties of the resulting optimal decision policies wereanalyzed, and a set of sufficient conditions for a monotone policy wereidentified.
