It is recommended to establish and use Energy Management Systems to ensure the continuity of improvement in energy efficiency studies. In this study, we have introduced an Energy Management System proposed for Istanbul urban electric rail transportation systems (Metro, Tram and Funicular lines), which has a major place in electricity consumption among transportation systems and which is the largest urban rail system in Turkey. In addition, examples of which data can be evaluated within the scope of EnYS with the measurements taken from the measurement and monitoring system established are presented and operational suggestions have been made for energy efficiency studies. In the study, the energy consumption of a total of 12 lines of Istanbul urban rail transportation systems, including 6 metro, 3 trams, 1 funicular, 2 cable car lines, were examined. It has been determined that the mobile systems (CER) constituted by the trains are the main consumer since they constitute 55-60% of the total consumption, and the remaining consumption is consumed at the stations referred to as auxiliary facilities. Within the scope of the EnMS, Energy Performance Indicators have been created to determine and compare the performances of the lines, and it is aimed to ensure that the improvement in energy efficiency is continuous and maximum. The CER performances of the lines were examined and it was calculated that up to 17% energy savings could be achieved in the first stage with the voyage time regulation. [ABSTRACT FROM AUTHOR]