Software process evolution at the SEL

The Software Engineering Laboratory of the National Aeronautics and Space Administration's Goddard Space Flight Center has been adapting, analyzing, and evolving software processes for the last 18 years (1976-94). Their approach is based on the Quality Improvement Paradigm, which is used to evaluate process effects on both product and people. The authors explain this approach as it was applied to reduce defects in code. In examining and adapting reading techniques, we go through a systematic process of evaluating the candidate process and refining its implementation through lessons learned from previous experiments and studies. As a result of this continuous, evolutionary process, we determined that we could successfully apply key elements of the cleanroom development method in the SEL environment, especially for projects involving fewer than 50000 lines of code (all references to lines of code refer to developed, not delivered, lines of code). We saw indications of lower error rates, higher productivity, a more complete and consistent set of code comments, and a redistribution of developer effort. Although we have not seen similar reliability and cost gains for larger efforts, we continue to investigate the cleanroom method's effect on them.>