Regression Testing – Everything You Need To Know

Regression Testing – Everything You Need To Know


Regression testing is a process that checks whether the software changes introduced in a new release can fix issues found in previous releases. Regression testing and retesting are performed to cover all possible scenarios, including those which might be hard to find during application development.

If you are working on any project. Then, before rolling out updates or modifications in your project, it’s crucial to run regression testing. This ensures that the changes made do not impact the existing functionality negatively.

What is Regression Testing?

Regression testing is a method of testing that aims to confirm that changes made to software don’t negatively impact previously functioning features. It’s used to ensure that software updates don’t break anything. It’s performed after the implementation of a new feature or functionality, and typically involves comparing an old version with a new one for signs of broken functionality.

Why use Regression Testing? 

Regression testing is a process to check if new software changes have any negative impact on the previously working features, it’s conducted to make sure that the software updates are functional. It verifies whether the changes made in the software have not affected the existing functionality of the system.

It is an important aspect of any application development process and can be performed by various tools such as Selenium, Cucumber and JMeter among others.

Types of Regression Testing

There are five distinct forms of regression testing, these are:

  • Corrective Testing
  • Progressive Testing
  • Selective Testing
  • Partial Testing and
  • Complete Testing (Retest)


Corrective testing is a process done to identify and fix errors in the software after it has been released. It is performed by developers on a daily basis, but also by testers once they are confident that their code works as intended.

The main difference between this kind of regression testing and traditional functional testing is that it focuses on identifying defects that were not found during a unit or system-level tests.


Progressive testing is a type of testing approach, where testing is done in different stages, starting from the least complex scenarios to the most complex ones. The goal of progressive testing is to identify and fix errors in the early stages of development and to identify potential problem areas early on in the process. Progressive testing is more efficient than complete testing, as it reduces the number of test scenarios.


Selective retesting is a technique that is used to test the software modules that have been changed in the new release. Selective retesting is also known as ‘module testing’ or ‘module level retesting’.

Partial testing

It usually focuses on a portion of the software system. It is used to test changes and additions to an existing portion of the system, rather than its entire functionality.

Partial testing can be performed by developers or QA testers; in most cases, it’s performed as part of functional or integration tests where there are already tests for specific problems – such as verifying that certain data has been entered correctly into a database table – and then having those specific tests verified again with partial application logic being added.

Complete testing

Complete testing is a type of testing where all possible scenarios and edge cases of a software application are tested and evaluated. It is a thorough testing approach where all possible variations and paths of execution are covered to check the software’s behaviour in different scenarios. This is a time-consuming process, but it is done to increase the reliability and correctness of the software.


Regression testing is a method of evaluating software changes to guarantee that they do not cause new defects or problems. It is a form of quality control done after updates to ensure the software still works as intended. It’s important because defects can cause difficulties in other parts of your system and prevent it from reaching its full potential.

Retesting is done to ensure that any changes made to an existing piece of code do not introduce new defects to your application or project.

Testing Tools for regression testing

  • Test management tools: This is the most common type of regression testing tool. It contains a database or an application that stores test cases, execution logs and report data for each test case.
  • Test automation tools: These are used to automate the process of running tests on a system or application with minimal human intervention. The output from such a tool can be visualized in real-time and presented as reports to show whether any errors were encountered during the testing phases.
  • Test case management tools: These are used to manage all kinds of information related to multiple kinds of tests being performed on different systems at once (such as QA). They help you identify bugs faster by keeping track of what went wrong in each step along the way so that you don’t miss any steps again when repeating them later on down the road!

Advantages of Regression Testing

  • Regression testing is a method of verifying that the previously working features of an application still work as expected after new changes have been made to the source code.
  • It helps you to find out if the new functionality is working as expected or not.
  • It helps in finding bugs, which were not detected during earlier stages of development and
  • Also helps in identifying those issues that were reported by users but couldn’t be identified during manual testing.

Disadvantages of Regression Testing

  • Regression testing is a time-consuming process, especially if you have many features to test.
  • It’s also expensive and may slow down your development cycle because developers will be spending more time on regression tests than writing new code.
  • In addition, not every bug can be caught by manual testing alone.
  • Some bugs might only surface when they’re being executed by people who use the system. If this happens during an actual deployment of your product or service. Then there’s no way for us humans (or machines) to tell which bugs were introduced by regression testing.

Management of configuration and regression testing

  • Define the scope of testing.
  • Define the test strategy.
  • Define the test plan and its associated phases (e.g., concept, acceptance).
  • Identify who will perform each phase of your process and when they should be completed. This includes identifying how much time is allotted for each phase (typically weeks or months).
  • Determine the number of tests to be done for your product by calculating the available resources and capacity for a single regression test cycle. This will help to identify how many people can work on a single project without affecting other concurrent projects. This will help avoid conflicts between teams and ensure all priorities are met.

Difference between Re-Testing and Regression Testing

Ensuring that new updates to software don’t cause unexpected issues is important and re-testing and regression testing are both methods used to achieve that.

Re-TestingRegression Testing
Re-testing checks the functionality of the software again after updates have been made.It is a more comprehensive approach to testing changes to the software. To ensure coverage of the software, a set of test cases are run during regression testing, including both new and previously tested functionality.
The goal of re-testing is to confirm that the functionality that was previously working still works as expected after the changes have been made.The objective of regression testing is to confirm that the software functions as intended after changes are made.

When should I perform regression testing?

  • The task of regression testing is carried out once the code has been altered, to ensure that any updates made do not interfere with the already existing features of the software.
  • Regression testing is performed after every build.
  • It is performed after every release.

How to Perform Regression Testing? 

Regression testing is performed after a change has been made in the codebase, and its goal is to verify that no new problems are introduced by such changes.

The steps for performing this testing include:

  • Creating test cases based on existing requirements (including all necessary constraints) – This ensures that each requirement can be met without affecting other requirements.
  • Executing these test cases with different combinations of inputs and expected outputs – This helps identify any bugs in your application’s functions as well as their dependencies from other parts of the system


Regression testing is a critical part of any software development process. It’s a way to ensure that your code and processes are functioning properly and that no bugs have been introduced with the release of new features or bug fixes. In this article we covered the basics of what regression testing is, why it’s important to perform thorough regression testing before releasing an update or patching existing code, and how long should these tests take. What tools should tool developers use? We also provided some tips on how best to keep track of them during their runtime.


What are the most critical aspects of regression testing?

Some critical aspects of regression testing include:

  1. Test case selection: choosing which test cases to run in order to provide adequate coverage of the software.
  2. Test environment: ensuring that the test environment is set up correctly and is identical to the production environment.
  3. Test data: Test data refers to the utilization of suitable data in order to test the functionality under examination.

What are the 3 techniques of regression testing?

There are many techniques for regression testing, but some common ones include:

  1. Re-testing: testing previously tested functionality after changes have been made to the software.
  2. Comparison testing: comparing the current behaviour of the software to its behaviour in a previous version.
  3. Regression test automation: It is the process of using automation tools to execute a collection of test cases.

What is required for regression testing?

The requirement for regression testing is to have a previous version of the software, test cases and/or test suite, and a method to record the behaviour of the software before and after the changes.

What are the steps of regression testing?

The steps of regression testing include:

  1. Identifying the changes made to the software
  2. Choosing the test cases to be run
  3. Testing includes setting up the testing environment, using specific data
  4. Compare the new results to the expected one.
  5. Investigating and resolving any discrepancies

How should regression testing be conducted?

The way regression testing should be conducted depends on the specific organization and product, but a best practice is to conduct regression testing frequently and thoroughly, in a dedicated environment that is as similar to the production environment as possible, and to use both manual and automated test techniques to ensure the most complete coverage of the software. Automation should be considered to cover the repetitive test cases, to save time and increase coverage.

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