Use of Defect Data

Defects information is just a gold mine. These are records of quality failures, which means a list of opportunities for improving quality on your future projects. If you are not documenting defects in your projects, then now is the time to start doing it. If you collect some information about defects (for example, after release or only on large projects), then you may want to improve this process.

Defect information, which may be useful for improving quality, includes the following questions:

• What was wrong? You need to solve the problem itself, not its symptoms. For example, looping is a symptom, and changing the loop index is a problem.
• When was the problem created? What kind of action in the development was its source? Was that a problem in the requirements? System design? Code? Testing?
• When was the problem identified? Maybe it was not immediately eliminated, but what interests us is how long it existed before we discovered it.
• How was this problem found? The method of detection can be implemented in a constantly used practice.
• Could it have been discovered before? Is there any Quality Control process that could reveal it if it were more effective?
• How much did it cost to fix this problem? This moment is very easy to underestimate. Make sure that you take into account the process of diagnosing the problem and all the work you have to do to eliminate it, including re-design, rewriting code, re-compiling, reworking tests, re-testing, re-release, releasing a patch, generating a report on the defect, report by project status, etc. (Do not forget even the possible costs of fixing a tarnished reputation in the software market)
• What kind of problem was this? When you have a huge number of defects, their categorization facilitates analysis and training.

When you analyze information about defects, then look for those defects that are detected regularly, and those costs for the elimination of which are high. It is precisely such defects that should be avoided in the future (or at least eliminated at an earlier stage of development), such tactics are guaranteed to help improve quality.