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Regression testing: A complete guide to ensure software quality and preventing defects

The goal of the testing procedure is to identify and correct software flaws. But frequently, even after a bug is resolved, new ones appear. Regression testing needs to begin as soon as this occurs. It ensures that a bug fix or code modification won’t lead to the rise of any new problems. As a consequence, regression tests are conducted by every company that sells software.

Regression testing is the process by which testers examine any areas of a software product that might have been negatively impacted by a patch after its application. This can be done directly or automatically by running a set of test cases through their paces. Regression testing can be done in various ways, but the most important thing is that it is done to guarantee the delivery of high-quality software. In this article, we will be discussing Regression testing and everything related to its procedure and how it is managed effectively to ensure that software quality remains unaffected and there are no defects.

When do you need to perform Regression testing?

Regression testing must be done every time new features or improvements are added to an existing codebase or application. It ensures that any new features included in an application already in use or updates to that application run without errors or problems. It is frequently challenging for developers and testers to locate every piece of code, significantly raising the risk of issues brought on by conflicting code. Regression testing their codebase (or application) allows them to release applications while exposing themselves to lower risk and discovering bugs more quickly.

Regression testing is crucial when some functionality is changed because failing to do so could jeopardize the codebase’s remaining functionality. Additionally, the removal of one flaw might make another one emerge. Using a mix of regression testing and troubleshooting in this situation, you can ensure that everything works as it should.

What and how often should you perform the Regression Testing procedure?

Several critical factors influence the regression testing strategy, including how frequently the application is updated, how significant the new change is, and which pre-existing sections it might affect.

You might find it beneficial to use some of these tried-and-true methods when performing regression testing:

By taking measurements or altering the scope of the work, ascertain whether the enhancement will likely impact the application.

Before starting automation testing, outline the test cases and scenarios to decide which should be tested automatically and which should be tested directly.

Regression testing procedures must cover all potential test cases and features they might impact.

When automating regression testing, you should concentrate your attention on the testing procedure, the technology, and the duties.

Make a risk estimate based on the size of your organization or project, the endeavor’s difficulty, and the enterprise’s weight.

How can regression risks be successfully managed without causing a delay in the product’s planned release?

The timeline for the product’s introduction could be significantly impacted by the risks related to regression testing. Here are some ideas for reducing the risks associated with regression:

Regression testing should not be started until all potential risks have been properly identified and assessed. After that, you’ll be able to focus all your efforts on the most crucial issues.

To reduce the impact of the risks that have been identified, implement risk mitigation methods. For instance, creating backups is one way to lower the risk that a specific threat will lead to data loss.

Regression risks can be structured by using tools like risk registries or risk management strategies. This will help ensure all possible risks are identified and monitored properly.

For stakeholders to make informed choices about the release schedule, it is crucial to keep them updated on any possible effects of regression risks.

Regression testing is a crucial step in the software development process, but it can be time- and money-consuming to carry it out. By automating some tests, regression testing can be made more efficient and less expensive while still providing a high degree of coverage. 

The following should be taken into account when deciding whether or not to implement regression tests:

Type of application being tested: Not all apps will be compatible with automated regression testing. For instance, automating the tests that rely on the user interface might be challenging if the application has a complex user interface.

Frequency of changes: If the application is frequently changed, automatic regression tests can help you save time in the long run.

Available resources: Automated regression testing requires significant initial time and resource investment. If project funding is limited, it is less likely that all regression tests will be completely automated.

The intended level of coverage: Automated regression tests can offer a high level of coverage if they are correctly created. However, manual testing may be necessary to complement automated testing and achieve full coverage.

If you’re a more experienced user, look at this guide to using Regression Intelligence.

How can you conduct regression testing on your various software applications and products?

Seek all the required tools and resources, such as test data, test scripts,  test cases, and more, to prepare for manual and automated testing. As a result, you’ll be able to carry out both kinds of checking.

To focus your testing efforts during regression testing on the areas of the application that the changes or upgrades will impact, you must explicitly identify those areas. To accomplish this, you must determine which parts of the application will be affected by the modifications or upgrades made to the application’s set modules.

Once you have identified the functionalities that will be impacted, you should confirm that the changes or improvements won’t harm those functionalities. Use both manual and automation tests as necessary. To carry out this validation, you can use human or automated tests.

Logging in, searching, and checking out are functionalities that should be tried because they are prone to the most common bugs. You can use various methods to find these regressions, including comparing the application’s output to the expected outcomes, running functional tests, and using automatic tools.

Changes to the Regression Testing Theme

Regression testing can be done in various ways, depending on your software development life cycle (SDLC) and the new feature or upgrade you intend to publish. However, a thorough knowledge of the available types is required to choose the best regression test.

The different types of regression testing are listed below:

Here is the list of Regression Testing methods mentioned below:

Corrective Regression Testing:

Corrective regression testing is one of the simpler types of regression testing, and it only requires a little work. No changes are made to the application’s original codebase during corrective regression testing and new features are introduced in the application. Instead of creating entirely new test cases, you should concentrate on validating the functionality that is already accessible and the associated test cases.

Selective Regression Testing

Selected regression testing, which assesses the effect of existing code and evaluates the influence of both new and existing code. Standard components like variables and functions have been added to the program so quick results can be seen without changing the process.

Unit Regression Testing

Unit regression testing, a crucial step in the regression testing method, involves evaluating the code separately. All other integrations, interactions, and dependencies are turned off while unit regression testing is being done, and the main attention is given to the code contained in a single unit. The testing is typically done when there is little traffic and during non-peak periods.

Progressive Regression Testing

Creating test scenarios is based on the requirements for a progressive regression test. New test cases can be created without impacting the product’s current code when only minor modifications are made.

Complete Regression Testing

It is conceivable that even comparatively small changes could significantly impact the final product. In situations like the one detailed here, complete regression testing is performed when significant changes have been made to the existing code. This type of testing helps in repairing modifications while following up with testing procedures.

Partial Regression Testing

Partial regression testing is a standard procedure whenever new code is introduced to an existing codebase. Allowing them to be tested without having an impact on the system aids in the finding of significant bugs that are already present in the code.

Retest-all Regression Testing

This type of regression testing is the procedure for re-evaluating the test suites just to ensure that there are no bugs. . For this type of checking, the quality assurance staff has to put in a lot of effort.

Difference Between Retesting and Regression testing

We will review the main differences between regression testing and retesting in this section of the article.

If you are new to the field of test automation, it’s possible that the words “Retesting” and “Regression testing” will seem to be equivalent to you. Both of these entities, though, are distinct from one another.

Retesting is a continuous process that entails recreating particular test cases to verify that any mistakes that had been previously identified have been fixed and that the functionality of the online product works as intended during final execution. The same unit tests are frequently run to ensure they are still valid when the code’s functionality is tested. Retesting, to put it another way, is performing the same manual or automated tests again to ensure the most recent build is functioning without any problems.

The regression technique is a type of technique for verifying the newly built when any code commit is introduced. A tester must ensure that the source code has not been compromised by introducing any new errors due to the software’s change or correction as part of this process. Once the Regression test package has been created, you can automate it using a tool, especially for automation testing. On the other hand, future testing is unaffected by this.


Regression tests must be performed after every modification, no matter how small, is made to the code. A number of techniques, including the Corrective Regression Testing Strategy, the Retest-All Strategy, the Progressive Regression Testing Strategy, and the Selective Strategies, can be used to achieve this.  Running regression tests can save you time and effort even though it consumes a lot of resources. It facilitates the work of developers and testers while also boosting output within the agile software development lifecycle. Remember that there are always tools like LambdaTest that can help you, even if you think regression testing is a challenging procedure.