Analysis of various development models has shown that there are aspects of the development of IT systems that are viewed in undiffferentiated form. Differentiation of the development process into the problem perception process and the problem mapping, plus the distinction between specification, prototype and test information forms the subject matter of the first part of this publication. In the second part, we will be addressing the relationships between the expressions as already delineated, and elucidating them by means of a new model-the Shall Prototype Test Development Model. The important aspect here is the introduction of the new expression Shall (elementary unit within a specification) plus a representation of the shall-centered approach to the development of prototypes, test procedures, and the reuse of solutions already devised. Use of the development model described here allows us to anticipate stringent development of hardware or software systems.