The records of failures that the electrical distribution companies have are the disconnections or outputs of service in a feeder, which present many events that are reflected in the operational and economic aspect. Until now they are issues that have not been solved, to mitigate disconnection times, that ' s the reason why the maintenance in an electric power distribution company has become today one of the most important decision-making activities, due to the need to increase the reliability, quality and security of the electric power supply to the final customer. Therefore, this study presents a methodology to prioritize the identification of feeders by their level of criticality, which is possible to obtain through the proposed index of weighted reliability WI. Once this index has been calculated for each feeder of the substation analyzed, a maintenance action can be prioritized with the highest values.