For the effective and efficient system development, it is provided of complex and diverse disciplines, analysis and design, points of views for decisions making, technical information management, assurance of products, and so on to be integrated and ensured. Systems engineering is conducted through a process and is implemented by tools based on relevant methodologies. Systems engineering environment should be provided to support the systems engineering process, method, and tools used on the project. In this paper, the essential environment in performing works in a organization applying systems engineering on the basis of system life cycle was reviewed. The present states on establishment of the systems engineering in Korea Railroad Research Institute were also examined with some reviews of other cases.