Most existing development procedures presume the generation of a detailed specification document prior to initialization of the design procedure. Detailed requirements for the development of real-time embedded computer systems are generally not available for much of the system when the design process must be initiated. The need exist for a mechanism to develop parts of the system that are high risk and least understood early in the design phase so that both users and developers can learn and refine the requirements. The proposed effort will develop such a mechanism. Based on high level requirements, the procedure will assist both the system designer and the end user in the formal definition of system requirements. In addition, by tightly coupling the output of the prototyping phase with the implementation software, the procedure becomes a strong tool for use during debug, verification testing, and subsequent system modifications. The proposed procedure is graphics based, and is designed to be easily translated into ADA for final system design and coding. Although interactive with the user, the procedure insures ADA-based structure is retained throughout the user of the procedure.