Regression Testing

Regression testing as the name suggests is used to test / check the effect of changes made in the code.
Most of the time the testing team is asked to check last minute changes in the code just before making a release to the client, in this situation the testing team needs to check only the affected areas.
So in short for the regression testing the testing team should get the input from the development team about the nature / amount of change in the fix so that testing team can first check the fix and then the side effects of the fix.

In fact the regression testing is the testing in which maximum automation can be done. The reason being the same set of test cases will be run on different builds multiple times.
But again the extent of automation depends on whether the test cases will remain applicable over the time, In case the automated test cases do not remain applicable for some amount of time then test engineers will end up in wasting time to automate and don’t get enough out of automation.

What is Regression testing?
Regression Testing is retesting unchanged segments of application. It involves rerunning tests that have been previously executed to ensure that the same results can be achieved currently as were achieved when the segment was last tested.The selective retesting of a software system that has been modified to ensure that any bugs have been fixed and that no other previously working functions have failed as a result of the reparations and that newly added features have not created problems with previous versions of the software. Also referred to as verification testing, regression testing is initiated after a programmer has attempted to fix a recognized problem or has added source code to a program that may have inadvertently introduced errors. It is a quality control measure to ensure that the newly modified code still complies with its specified requirements and that unmodified code has not been affected by the maintenance activity.

What do you do during Regression testing?
- Rerunning of previously conducted tests
- Reviewing previously prepared manual procedures
- Comparing the current test results with the previously executed test results

What are the tools available for Regression testing?
Although the process is simple i.e. the test cases that have been prepared can be used and the expected results are also known, if the process is not automated it can be very time-consuming and tedious operation.

Some of the tools available for regression testing are:
Record and Playback tools – Here the previously executed scripts can be rerun to verify whether the same set of results are obtained. E.g. Rational Robot

What are the end goals of Regression testing?
- To ensure that the unchanged system segments function properly
- To ensure that the previously prepared manual procedures remain correct after the changes have been made to the application system
- To verify that the data dictionary of data elements that have been changed is correct