Difference Between Retesting and Regression Testing

Retesting vs Regression Testing

Retesting and regression testing are two methodologies in software testing. In any software development cycle, testing plays a major role. The testing process is carried out in different methodologies to ensure the performance of the software, identify and fix the bugs, and to verify that it meets the customer requirements.

More about Retesting

Retesting is more of an informal term used in the industry, and it means to test a single module or specific segment after it has been fixed on finding bugs from a previous test. This test may be carried out repeatedly to ensure that the component is functioning properly.

The basic distinction to be made here is, that retesting does not concern about the effect of the fix, patch, or other alternation to the other components in the system.

More about Regression Testing

The regression testing procedure is for uncovering new bugs or ‘regressions’ in existing functional and non-functional areas of a software system after changes has been made, such as enhancements, patches, or configuration changes. Regression testing can be used as an efficient means of testing a software system, systematically selecting the required minimum number of tests to ensure the changes are not affecting the particular module, or related modules.

Its main focus is to verify whether the changes affect the other components of the software and has introduced new bugs to the system. Rerunning the tests is one of the methods in regression testing process, to ensure the previously fixed bugs have not reappeared.

What is the difference between Retesting and Regression Testing?

• Retesting is a process for verifying the fixes made to a specific module or an element while regression testing is a process for checking the effect of the changes in functionality of the software system as a whole after changes to the system has been made. The effect of the fix on the other component of the system is the main focus.

• Retesting process is planned based on the fixes made to the system, and it can be a generic test to check the functionality of the whole system or check a specific region where the changes are made.

• Retesting involves rerunning previous test cases which were failures, and regression testing involves rerunning tests that were passed in earlier builds of the software system.

• Retesting concerns rerunning failed tests that are incorporated with fixes for the faults in the system, while the regression testing concerns only the regression aspect of the software system as a result of the changes.

• Regression testing is done after the retesting process.

• In projects where ample resources are available, the regression testing and retesting is carried out simultaneously.