In this article, the reliability model and the opportunistic maintenance optimization model are formulated for the preset self-repairing mechanism which is artificially designed and applied to many engineering systems. The preset self-repairing mechanism is first introduced into the reliability model, and a series system consisting of two units is built to describe the proposed model. One unit in the system is subject to external shocks and has the preset self-repairing mechanism, the other does not have the recovery mechanism and its lifetime distribution follows exponential distribution. For the system, the analytical expression of reliability is derived, and a maintenance optimization model taking the long-run average cost per unit time as objective function is established. The decision parameters of the maintenance policy are preventive and opportunistic degradation levels. Besides, a preventive maintenance policy is proposed for comparison with the opportunistic maintenance policy. Finally, the numerical examples are provided to obtain the optimal decision parameters and demonstrate the effectiveness of opportunistic maintenance policies.
