Comparative cost-benefit analysis of four retrial systems with preventive maintenance and unreliable service station

In various industrial problems, repairable models have been widely employed to derive performance measures. The current investigation compares four unreliable retrial systems with preventive maintenance. The objective is to offer a proper analysis procedure helpful for managers to determine the best configuration resulting in a better performance. A potential application in which the proposed model can be applied is provided. For each system, the state-transition diagram and associated differential-difference equations are presented. Using the Laplace-Stieltjes transform, we derive the explicit formulas for the mean time-to-failure and the steady-state availability, commonly considered critical criteria. Numerical results are tabulated and displayed graphically, and then a comparative cost-benefit analysis is performed. Finally, observed insights into decision-making are provided.