7.1 DEVELOPING THE SYSTEM REQUIREMENTS
Chapter 6 discussed the process of needs analysis, which is intended to provide a well-documented justification for initiating the development of a new system. The process also produces a set of operational requirements (or objectives) that describe what the new system must be designed to do. Assuming that those responsible for authorizing the initiation of a system development have been persuaded that these preliminary requirements are reasonable and attainable within the constraints imposed by time, money, and other external constraints, the conditions have been achieved for taking the next step in the development of a new system.
The principal objective of the concept exploration phase, as defined here, is to convert the operationally oriented view of the system derived in the needs analysis phase into an engineering-oriented view required in the concept definition and subsequent phases of development. This conversion is necessary to provide an explicit and quantifiable basis for selecting an acceptable functional and physical system concept, and then for guiding its evolution into a physical model of the system. It must be remembered, however, that the performance requirements are an interpretation, not a replacement of operational requirements.
As in the case of operational requirements, the derivation of system performance requirements must also simultaneously consider system concepts that could meet them. However, ...