The purpose of the software detailed design and unit construction process is to provide an evaluated detailed design for the software components and to specify and to produce the software units.

The techniques suggested in the standard can be justified on the basis that they make the resulting code more reliable, less prone to error, easier to test, and/or easier to maintain. For example, language subsets such as MISRA C restrict the use of a programming language to those elements known to be least susceptible to causing problems (Figure 3).

Figure 3: Highlighting violated coding rules and guidelines in the LDRA tool suite

Bidirectional traceability between software detailed design and software units is a key requirement of the standard. Automating that traceability reduces both management overhead and the potential for error, particularly when unanticipated changes arise. In such circumstances, impact analysis reports help to quantify the overhead associated with such changes and ensure that they are implemented in full (Figure 4).

Figure 4: Impact analysis report generated by the LDRA tool suite

SWE.3 Software Detailed Design and Unit Construction