The railway system consists of many items such as sub-systems, equipments and parts to accomplish the required function. Also the railway system is very complex system that these items are connected with interface among items. According with this complexity, the process of system engineering is applied to the construction of new railway project to manage systematically. In addition, the research about system engineering is progressing in recent. The RAMS management is one part of system engineering, and is to assure the required safety and performance. Also, this RAMS should be managed through system life cycle. This paper show the case study of management of RAMS during construction and operation phase in respect of system life cycle. As a result of this research, the best way of RAMS management based on system engineering in operation phase for railway system is suggested.