4.4 Structured Software Designs

4.4.1 Background

Software structures can be derived in many ways, each one has its supporters and critics. But how do you make sense of the various claims and counter-claims? Well, the real test of any method is to see how well it works in practice. Judged against this, techniques based on functional structuring of programs rate highly.

"Structured software design" is here used as a general characteristic (generic) term, covering a number of design methodologies. It belongs firmly in the Yourdon-Constantine-Myers-Meiler-Ward-Mellor-DeMarco school of design, its premise being that a program takes its shape from the functions carried out by the system. The overall design approach is based on many of the ideas and concepts discussed earlier in this chapter. However, it is very important that you recognize the method is essentially a program- (and not system-) oriented one. Please read this last sentence again!

We start by defining system...