LAUSR

To optimize the maintenance of complex systems of metro trains, the variation trends of the failure rates of components under imperfect maintenance are identified, and the maintenance cycle of components under reliability constraints are determined based on the concept of reliability-centered maintenance. An optimal maintenance plan for the components that is based on maintenance economy and availability then is developed. Lastly, opportunistic maintenance with time dependency is introduced, and the maintenance optimization model for complex systems is constructed for the special application environment and maintenance mode of metro trains. The model constrained by the opportunistic maintenance threshold, ${\Delta}{t}$, to optimize the maintenance costs and availabilities of metro trains is established. The multicomponent joint opportunistic maintenance model in this article is based on the constraints of reliability and availability, which not only has high economy but also has practical application significance. The door subsystem of a Nanning Rail Transit Line 1 train is simulated as an example in this article. The opportunistic maintenance strategy and preventive group maintenance strategy are compared. The simulation results demonstrate that under the premise that the reliability constraints of components are satisfied, the maintenance of the metro train complex system can be effectively optimized by the model; in addition, the maintenance costs are reduced, the availability of metro trains is improved, and a metro train maintenance plan is scientifically formulated.