Asset management is a crucial approach for the performance of organizations as they seek to align technical aspects of engineering with financial concepts to optimize the life cycle of a machine. The Equipment Replacement Problem is one of the issues addressed within asset management studies that aims to decide the best option between maintaining or replacing equipment in a given time interval. One of the methodologies that have been used in the literature to solve this problem is Dynamic Programming, which is based on finding partial solutions in a series of stages of the problem until reaching the global optimum. This work aimed to determine a substitution curve for a set of locomotives of a company in the railway sector, considering an age limit for them to circulate and their revenue and cost history over the years. The results achieved allowed the company to know the best way to optimize its capital, taking into account the financial impacts if it chooses to anticipate or postpone the optimal moment for the replacement of assets.