One of the most serious problems in connection with the use of computers in organizations today, is that the properties of computer based systems (CBS) do not meet the requirements raised during the systems development process (SDP). This paper focuses on one of the functions of systems development (SD): Property determination. This paper develops a framework which consists of a definition of a systems development method (SDM) and a devision of property determination into four subfunctions. The prototyping approach is evaluated through the use of the framework. Refs.