Abstarct: Maintenance is considered as an important activity in today world industry, so implementing an efficient model is of great importance. The traction inverter system is used as an asynchronous motors drive in the tramway system of the urban railway. The continuous operation of the urban transport system is directly related to the correct operation of this equipment. In this thesis, the recommendations of the manufacturer, certified expert of the urban railway of Mashhad, as well as by direct visiting of the system, were used for implementing the RCM II method. The important steps to be taken include the selection of equipment, the preparation of a list of key functions, the identification of failures (operation failure, the causes of failure, the effects of failure and the consequences of failure), the choice of effective and practical repair tactics for the inverter and, finally, the planning and implementation of the selected tactics of the traction inverter. This dissertation focuses on the traction inverter section as a vital system in the urban railway of Mashhad. An innovative method, baxsed on previous articles and the RCM II decision table, has been used to prioritize equipment in the maintenance plan, which considers the economic and technical criteria. The results and ideas directly use in the maintenance of the urban railway of Mashhad, in addition, can be fully utilized in other similar systems and rail transport. It indicates that the RCM II not only increases the safety and availability of the system but also decreases the cost of maintenance significantly.