Currently, the inclusion of fuzzy inference systems in the modeling of maintenance evaluation expands the possibilities of making decisions, comprehensive management and reduces the risk of human error. The research problem lies in: How to contribute to the improvement of the evaluation of maintenance management variables, to measure management capacity? The objective is to develop a mathematical model supported by fuzzy logic, for the evaluation of maintenance management variables and their capacity. The research shows the results obtained from the application of a mathematical model based on Fuzzy Logic in Aqueduct and Sewer Companies, to evaluate their maintenance management capacity. The use of these models allows the introduction of qualitative variables, the incorporation of knowledge and the assessment of experts that facilitate modeling in an environment of subjectivity and uncertainty. Techniques and tools such as: interviews, questionnaires, cluster analysis, ANOVA method, Ishikawa diagram, among others, were used to collect and process primary data. The results of the application of the tool showed that companies carry out poor maintenance management, with the most affected variables being: training, computer applications, as well as supplies and tools.