10.5 Defect Analysis and Prevention

We have seen that defects are introduced during development and are removed by the various quality control tasks in the process. Whereas the focus of the quality control tasks it to identify and remove the defects, the aim of defect prevention is to learn from defects found so far on the project and prevent defects from getting injected in the rest of the project. Some forms of defect prevention are naturally practiced and in a sense the goal of all standards, methodologies, and rules, is basically to prevent defects. However, when actual defect data is available, more effective defect prevention is possible through defect data analysis [76,75]. Here we discuss an approach for doing focused defect prevention, based on practices of a commercial organization [97].

Defects analysis and prevention can be done at the organization level as well as at the project level. At the organization level, analysis of defects can lead to enhancements of organization-wide checklists, processes, or training. Defects analysis at the project level, aims to learn from defects found so far on the project and prevent defects in the rest of the project. Here we discuss only project-level analysis.

The main reason behind any defect prevention activity is to improve quality and improve productivity. Quality improves as with fewer defects injected, with the same effectiveness of quality control processes, the final system will have fewer defects. Productivity improves as lesser effort is spent on removing defects.

For a project, defect analysis for...