Change related testing ensures that previously corrected bugs does not accidentally appeares in a new version of the software. There are two subtypes of Change related testing:
- Confirmation testing (Re-testing)
- Regression testing.
How Confirmation testing and Regression testing differ?
They are executed in order with one after another. Firstly we perform Confirmation testing to verify if the reported bugs has been fixed. The test case that originally detected the bug is executed again and this time we expect it to pass with no problem. Then Regression testing is executed to ensure no new defects created by the correction of old ones.
Regression testing is responsible for the overall stability and functionality of the existing features.
Confirmation Testing is responsible for retesting reported bug fixes.