Defects remain undetected due to Test Gaps
It is no secret that new or changed code often causes defects. Therefore, testers attach great importance to thoroughly testing new and changed functionality. Unfortunately, this does not work reliably in practice.
In a study with Munich Re, we accompanied two releases of a business information system. In both releases over 50% of the changes were not tested. These untested changes had a 5x higher defect probability.
This gap in testing, which left over half of the changes untested, would have gone undetected until release without tool support - even though Munich Re uses a very structured, multi-stage testing process. The reason for these Test Gaps is that information about changes is spread across different systems and teams. In addition, it is usually incomplete.
Test Gap analysis shows you all untested changes, so you can close these gaps before release.