A Repairable System Supported by Two Spare Units and Serviced by Two Types of Repairers

We study a one-unit repairable system, supported by two identical spare units on cold standby, and serviced types of repairers. The model applies, for instance, to ANSI (American National Standard Institute) centrifugal pumps in chemical plant. failed unit undergoes repair either an in-house repairer within random or deterministic patience time, else visiting expert repairer. repairs one all before leaving, does so faster but at higher cost rate than the regular Four models arise depending number done nature time. compare these based limiting availability $A_{\infty}$, profit per time $\omega$, using semi-Markov processes, when distributions are exponential. As anticipated, maximize should units. To suitably chosen is better Furthermore, given parameters, we determine optimum complete, order $\omega$.