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.