These two concepts are closely linked and essential to managing defects.
• Recidivism is the introduction of new errors in the attempt (successful or
unsuccessful) to correct a defect. Recidivism is often the result of inadequate or
incomplete analysis of the reported defect, leading to an inappropriate solution.
This solution may, in fact, cause the defect to be masked (the test cases provided no
longer trigger the error) but not resolved (the error will still be triggered by another
set of circumstances). A high rate of recidivism (the ratio of injected defect to all
defects) indicates a problem with the analysis process. As this is one of the key
areas for the Business Analyst, this metric is one that should receive their careful
attention.
• Persistent Failure Rate is the name for defects that are not resolved by new releases
of the product to the testers as compared to the total defects reported. A high
Persistent Failure Rate is often coupled with a growing defect backlog and should
be a signal that the project is experience significant quality problems. Because the
Persistent Failure Rate can be measured beginning very early in the life of the product, it is an excellent early indicator of quality problems. These will lead to
schedule and budget problems that may not be obvious that early in the project.