Steady-state availability analysis of repairable mechanical systems with opportunistic maintenance by using Semi-Markov process

In this paper, a methodology for analysis of steady-state availability of repairable mechanical systems with opportunistic maintenance is presented, which is based on Semi-Markov process (SMP). SMP models; combining corrective maintenance with the opportunistic maintenance are proposed. The opportunistic maintenance is based on the condition of the component. An analytical framework is suggested for the solution of the SMP models. System steady-state availability is evaluated and compared in three cases of corrective maintenance; perfect, minimal and imperfect repairs; with and without opportunistic maintenance. The benefits of opportunistic maintenance are quantified in terms of the increased system availability. The proposed methodology is useful for maintenance engineers in implementing appropriate maintenance policy. The methodology is also helpful to designers to target a desired value of the system availability for the type and level of repair. The proposed methodology is demonstrated for a system, consisting of a centrifugal pump and the transmission unit in a series configuration.