This document was prepared by the UIC Energy and Electrical Traction Experts Group of the Rail System Forum to provide all railways with guidelines for the evaluation of energy system incidents based on uniform criteria and common objectives. The energy system has been divided into its main sub-parts in order to clarify the different incident causes and provide feedback on maintenance activities. At the same time the classification, statistics and relevant databases regarding main failures have been identified, along with the data to be examined to facilitate the management of energy system incidents, which will in turn allow all the relevant railway sectors/companies to focus their attention and improve their organisational strategies.