williams@kirk.dec.com (John Williams 223-3402) (07/22/86)
The design process is actually both. The top and the bottom represent the limits of the designer's knowledge, and are given a priori to the design. The designer then works towards the middle to some form of representative block diagram. This allows two things to happen: 1) System functionality is defined, and a design can be evaluated from an environmental standpoint. 2) Primitive components are selected by virtue of their quality, choosing the best components for the best design. John.