Regression Testing in Software Engineering

Regression testing is a vital part of software development that checks if recent changes to the code have affected existing features. It involves running tests again on updated software to make sure everything still works as expected. 

The main goal is to find any unintended problems caused by new code or updates. By doing this, regression testing helps keep software reliable and high-quality by catching issues early on, reducing the chances of errors when the software is in use. 

Big Bang Approach in Software Testing

What is Regression Testing ?

  • In software engineering, regression refers to the “return of a bug”.Regression is the term which means re-testing the modified parts of the application.
  • Regression Testing is a type of performance testing which is used to check the software functionality after changes.
  • This testing is used to ensure that changes in the existing code or modified code does not impact the existing functionality of the software product.
  • It is done when new features are added in the software or changes are made in the requirements or fixing the defects/bugs.
  • This is done to make sure that the application works correctly with the modified functionality.
  • Previous test cases are re-executed to verify the effect of change.
  • Automated test cases are executed because executing test cases manually are time consuming. Hence automated test cases in time saving and efficient method.

Types of Regression Testing 

There are different types of regression testing:

  • Unit Regression Testing: Testing individual units or components of the software.
  • Partial Regression Testing: Selective testing of features affected by recent changes.
  • Complete Regression Testing: Testing the entire application to ensure comprehensive coverage.

Need of Regression Testing :

  • New features are added in the software system
  • To fix the defects/bugs
  • When changes in the environment
  • When changes in the requirements and code is modified
  • When fix the performance issues of the software 

Levels Applicable For :

  • Unit Testing
  • Integration Testing
  • System Testing
  • Acceptance Testing

Regression Testing Tools : 

  • Ranorex Studio
  • Testim
  • actiWate
  • Selenium
  • vTest
  • Watir
  • TimeShiftX
  • SilkTest
  • Quick Test Professional (QTP)
  • Rational Functional Tester (RFT)

Advantages of Regression Testing :

  • It ensures that new functionality does not impact the existing functionality of the software product.
  • It improves the quality of the software system.
  • This testing increase the performance of the application.
  • It provides more reliability.
  • Automation test cases are executed on this testing.
  • This testing is ideal for small applications.

Disadvantages of Regression Testing :

  • If manual test cases are executed then it can be time-consuming.
  • It has to be done if small changes in the code are made.
  • It can be resource consuming if automated tools are not used. 
  • Select the best automation tool for continuous regression. 
  • It can be costly to test.
  • Defects are find at a very late stage

Need of Regression Testing :

  • New features are added in the software system
  • To fix the defects/bugs
  • When changes in the environment
  • When changes in the requirements and code is modified
  • When fix the performance issues of the software 

Levels Applicable For :

  • Unit Testing
  • Integration Testing
  • System Testing
  • Acceptance Testing

Regression Testing Tools : 

  • Ranorex Studio
  • Testim
  • actiWate
  • Selenium
  • vTest
  • Watir
  • TimeShiftX
  • SilkTest
  • Quick Test Professional (QTP)
  • Rational Functional Tester (RFT)

Advantages of Regression Testing :

  • It ensures that new functionality does not impact the existing functionality of the software product.
  • It improves the quality of the software system.
  • This testing increase the performance of the application.
  • It provides more reliability.
  • Automation test cases are executed on this testing.
  • This testing is ideal for small applications.

Disadvantages of Regression Testing :

  • If manual test cases are executed then it can be time-consuming.
  • It has to be done if small changes in the code are made.
  • It can be resource consuming if automated tools are not used. 
  • Select the best automation tool for continuous regression. 
  • It can be costly to test.
  • Defects are find at a very late stage