Rolling stock has a limited life span during which it can provide efficient service. Faced with today’s budget constraints and economic slowdown, all railroad or transit operators will eventually face the following questions: What is the most suitable equipment available to replace the existing equipment for the particular service? What is the most economic way of procuring the required fleet? To answer those questions, various railroad agencies and transit operators used diversified measures such as capacity demanded by the ridership forecast, performance afforded by the proposed equipment, or the operating and capital cost associated with certain rolling stock configurations. However, comprehensive analyses based on all three factors mentioned above are rare, even though it is agreed that all those factors affect railroad services simultaneously and they all should be considered in the rolling stock planning process. To fill the gap, this paper describes a comprehensive approach to select long-term rolling stock for commuter services. This approach not only considers the performance of the proposed equipment but also evaluates the life cycle costs of the proposed fleet configuration. A case study of rolling stock planning for a commuter rail service is included to demonstrate the practical application of the suggested approach. Combining the train performance simulation (TPS) and life cycle cost (LCC) analysis, the proposed approach derives an optimal balance between service costs and service quality. Moreover, by incorporating the timing of the new equipment purchases into the life cycle cost, this approach further maximizes the return on capital investment for transit agencies.