During development systems undergo changes. System parts that have already passed testing can be affected by the changes, so they need to be re-tested. The process of selecting areas and re-testing of what was tested before is called Regression testing.
We used to perform analysis for the areas of risk based on our own experience, feedback from development and formal criteria.
Our own experience can help us define risky areas based on our knowledge of the system structure or past experience with system. We may know that some part of the product is very complex, so changes in it require careful examining of the remaining functionality. We may also know that component that was changed is used in several components, so all of them are now the subject for regression testing.
Selecting tests for regression testing also requires certain knowledge and experience. The easiest way is to re-run all the tests but this is also the most expensive solution. Careful selection of tests for re-running is the key for getting the most for your buck. EffectiveSoft offers testing processes that helps making selection for regression tests with one click.
Test automation is a big help for regression testing. You may save a lot of your budget having your major regression tests automated.