Regression Testing ?

Regression Testing
Testing of a previously tested program following modification to ensure that defects have not been introduced or uncovered in unchanged areas of the software, as a result of the changes made is called Regression Testing.
 Regression test is a system-wide test whose main purpose is to ensure that a small change in one part of the system does not break existing functionality elsewhere in the system. If you consider regression as unintended change, then this type of testing is the process of hunting for those changes. In simple terms, it is all about making sure that old bugs don’t come back to haunt you.
Benefits of Regression Testing
Conducting regression tests benefits companies in a number of ways such as:
1) It increases the chance of detecting bugs caused by changes to software and application
2) It can help catch defects early and thus reduce the cost to resolve them
3) Helps in researching unwanted side effects that might have been occurred due to a new operating environment
4) Ensures better performing software due to early identification of bugs and errors
5) Most importantly, it verifies that code changes do not re-introduce old defects

Regression testing ensures the correctness of the software so that the best version of the product is released to the market. However, in the real world, designing and maintaining a near-infinite set of regression tests is just not feasible. So you should know when to apply regression testing.

Whn to apply Regression Testing?
It is recommended to perform regression testing on the occurrence of the following events:

• When new functionalities are added
• In case of change requirements
• When there is a defect fix
• When there are performance issues
• In case of environment changes
• When there is a patch fix