Abstract: Simulation based acquisition (SBA) is a new technique emerged in the mid1990s. It is an acquisition process in which DoD and industry are enabled by robust, collaborative use of simulation technology that is integrated across acquisition phases and programs. The definition, technical features and key techniques of SBA are introduced. The architecture of SBA system for complex product is presented, and then the functions and characteristics of each component of this system are discussed. Finally the strategy to implement SBA is given.