Vehicles connected to electric systems are considered “plug-in” vehicles. They can be an integral part of a microgrid. Ground vehicles have become more electrified over time, providing electrical power for the propulsion system (hybrid) and a complex suite of auxiliary power systems, enhancing their use in microgrids. Optimizing the microgrid system for performance and reliability considering many external loads and sources is a challenging problem. This is especially true when the plug-in vehicles may enter and leave the microgrid randomly becoming either sources or loads. The microgrid is a repairable system. Recent work has shown that multiple metrics are needed to fully account for the performance of repairable systems under uncertainty. In this paper, we propose a decision-based framework to design and maintain repairable systems for optimal performance and reliability using a set of metrics such as minimum failure free period (MFFP), number of failures in planning horizon, and cost. Optimal tradeoffs among a minimal set of metrics (MSOM) can be used in the design and maintenance of these systems. The optimal solution includes the initial design, the system maintenance throughout the planning horizon, and the protocol to operate the system. Critical remote military installations with plug-in vehicles connected to the microgrids require careful consideration of cost and repair strategies because of logistical challenges in performing repairs and supplying necessary spare parts in unsafe locations. We show how a MSOM helps to solve the complex optimization problem of finding the best microgrid power management strategy considering performance, reliability, and cost.