Software quality enhancement can be achieved in the near term through use of a systematic program testing methodology. The methodology attempts to relate functional software testcases with formal software specifications as a means to achieve correspondence between the software and its specifications. To do this requires generation of appropriate testcase data.
Automatic testcase generation is based on
a priori
knowledge of two forms of internal structure information: a representation of the tree of subschema automatically identified from within each program text, and a representation of the iteration structure of each subschema. This partition of a large program allows for efficient and effective automatic testcase generation using straightforward backtracking techniques.
During backtracking a number of simplifying, consolidating, and consistency analyses are applied. The result is either (1) early recognition of the impossibility of a particular program flow, or (2) efficient generation of input variable specifications which cause the testcase to traverse each portion of the required program flow.
A number of machine output examples of the backtracking facility are given, and the general effectiveness of the entire process is discussed.