Why we do regression testing?

Answer 1

Regression testing is a critical part of any integration testing procedure because you want to verify that the change made did not introduce some unexpected effect. Regression testing, then, is the verification that things still work, and implementation testing is verification that new things work.

In the worst case, regression testing might require a full blown acceptance test, and that might take much longer to do than the testing for the one or two lines of code that you changed. Modularization, good design, and good record keeping can minimize regression testing because you might be able to argue that certain things don't need to be retested in one area if you changed something in another area.

You can also argue for minimization of regression testing if you have robust code controls in place. Most large shops will have an automated compilation sequence based on submittal of controlled changes to code. You never want to make a production change on the fly, unless it is an emergency.

Answer 2

when the tester come's to conformation that the big is fixed, then he starts Regression testing on that modified build. in this testing, the tester test's or checks whether the modified build is showing any impact on other application or not.. means whether new application or functionality is effecting other application or not.the tester checks after fixation of bug,we got any side effects in application or not... why because , during the bug fixing some parts of coding may be changed or functionality mat be manipulated.. in this case the old test cases will up-dated or completely re-written according to new feauter of application where bug fixed area.

Answer 3

Regression Testing is required when there is a

-Change in requirements and code is modified according to the requirement

-New feature is added to the software

-Defect fixing

-Performance issue fix