<< Blog

Importance of Automated Regression Testing in SDLC

April 19, 2019

Know More About Automated Regression Testing

Regression testing is a testing that is done to confirm that a code change in the software does not affect the existing functionality of the product.

Automated Regression Testing is a type of software testing in which test cases are re-implemented in order to verify whether the previous functionality of the application is working good and the recent changes have not presented any new bugs. This test can be executed on the latest build when there is a critical change in the original functionality that too even in a solitary bug fix.

Need for Regression Testing

  • When the code is modified during SDLC
  • If the client’s requirement changes mid-cycle
  • When software enhancement is undertaken
  • Bug fixing at a speed

How does Regression Testing Work?

Software maintenance is a kind of an activity which includes modifications, error corrections, optimization, the addition of the new features to the software, deletion of existing features and unwanted or unexpected errors may arise due to these demands. And, to handle such errors regression testing comes into the picture. It is being carried out with the following techniques:

Regression Testing Techniques

Retest All

All the test cases from the entire test suite are re-executed to check whether the code runs properly without any error after the updating. It is time-consuming and expensive.

Regression Test Selection

Selective test cases are re-executed from the test suite based on code change in the module. Test cases are divided into two categories:

  • Reusable test cases: Used in future regression cycle.
  • Obsolete test cases: Not used in future regression cycle.

Test Case Prioritization

Prioritize the test cases relying upon business impact, crucial & commonly used functionalities. Test cases selection based on priority will considerably decrease the regression test suite.


Hybrid technique is a combination of Regression Test Selection and Test Case Prioritization. Instead of executing all test cases from the test suite it is better to execute selected test cases based on their priority.

Types of Regression Tests

1. Unit Regression: Unit Regression is done during the unit testing stage and code are tested in solitude i.e. any dependencies on the unit to be tested are hindered so that the unit can be tested separately without any flaws.

2. Partial Regression: Partial regression is done to confirm whether the code works precisely even when the changes have been done in the code and that unit is combined with the already existing code.

3. Complete Regression: Complete Regression testing is done when a change in the code is done on various modules and also if the change impacts in any other module are said to undetermined. So, the complete product is regressed to check any changes because of the modified code.

Selecting Test Cases for Regression Testing

Last minute bug fixing or updating the application may cause side effects so the selection of the test cases is crucial. Similarly, there are also certain challenges of Regression testing which needs to be managed by various companies and their testers during the planning and executing the regression tests.

Effective regression testing can be done by selecting the following test cases:

  • Test cases have frequent defects
  • Functionality is more visible to the users
  • Test cases verifying the core features of the product
  • Test cases undergoing frequent changes
  • Complex test cases
  • Boundary value test cases

There is a misconception that re-testing and regression are similar, they both are totally different in nature.

Regression Testing vs. Re-testing

Re-testing is carried out to confirm that the test cases that failed in final execution are passing after fixing the defect. Priority of retesting is higher than regression testing so it is carried out first. Retesting is planned testing and is done only for failed test cases. Test cases for retesting cannot be obtained before starting the test.

Regression testing is carried out to check whether recent program change, not adversely affected existing features. It is not used for defect verification. Regression testing can be carried out parallel to retesting. It is also known as generic testing and is done for successful test cases.

Automation for regression testing can be done, as manual testing could be expensive and time-consuming. Automation testing is very important for testers as it saves time and generates specific and efficient end-product. Automation also faces some issues which are listed below.

Limitations of Automation

Software Test Automation eliminates manual labor, but it needs a lot of skilled resources to execute various test scenarios. Companies need to hire testers having substantial coding skills. There are two types of code running simultaneously in case of automation testing. One is testing code written by testers and other is application code which is being tested and written by developers.

If regression testing simply becomes automated, then the whole point of doing it may exhaust. One will end up with a clear software development unknowingly ignoring vast swaths of application. Introducing some amount of manual testing and GUI based IDEs to the system will take automation to another level.

Future of Regression

Regression is one part of a comprehensive testing methodology which is cost-effective and efficient. The main aim of regression testing is to check the changes in the code that doesn’t affect the application.

Irrespective of the software development and quality assurance strategies an organization adopts, if it focuses on crafting clear and diverse testing strategies with automated regression testing at its core, it helps to optimize the expenses incurred, keeping the team on the track and most importantly it will remove unexpected bugs from damaging the product.

Testing Whiz is one of the leading regression test automation tools, which provides traceability reports and matrices, supports reusable test cases and deliver a bug-free product to the client. To know more about Testing Whiz, you can contact our experts on 1-855-699-6600 or you can drop us an email on info@testing-whiz.com


TestingWhiz is committed to provide an innovative and automated software testing solution to the global enterprises and software companies for their web, mobile and cloud applications.


Cygnet Infotech LLC,
125 Village Boulevard,
Suite 315, Princeton,
NJ 08540, USA