What is Regression Testing

Have you ever wondered what happens to a software application after it undergoes numerous changes or updates? How can we be sure that these modifications haven’t introduced new bugs or disrupted existing functionality? That’s where regression testing steps in to save the day! 

Imagine that your program has a bug that is found and fixed. You can now update or add new features. Without regression testing, you risk unintentionally reintroducing the bug or creating new problems. Regression testing aids in keeping your software’s integrity. We will explore the complexities of regression testing in this article and when and how it needs to be carried out.

What is Regression Testing

Regression testing is a software testing approach to ensure that a program functions as intended following any code updates, revisions, enhancements, or optimizations. It is a crucial step in software development because it enables programmers to find unforeseen errors that may appear in a program due to alterations, improvements, or expansions to the current codebase.

By monitoring the functionality of the current features, regression testing ensures the overall stability of the software product. After each new code update, it is necessary to ensure the system can support and endure numerous upgrades.

Technically speaking, a change in the code may result in a change in dependencies, which might result in errors or malfunctions in the software. Regression testing is used to mitigate these hazards. It enables experts to check if the already created and tested code continues functioning when new features or code changes are implemented.

Regression Testing Why is it Necessary

Regression testing is required anytime the code is altered to ascertain whether the updated code will impact other areas of the software program. It is also necessary when the software program includes a new feature. Regression tests may also be run when a performance or functional flaw is corrected.

When Should This Test Be Done

Regression testing is often carried out following the validation of updates or new features. However, it’s not always the case. These tests must be added to the daily test cycle for the release, which will take months to complete. Regression tests can be run when Functional Testing for the modifications is complete for weekly releases.

Regression testing is done by developers when a flaw in any functionality is repaired. This is done to see if the adjustments to address the problem have impacted other connected features. It is necessary every time the product interfaces with a new external system.

Types of Regression Testing

1. Complete Regression Testing

Complete regression testing involves running the entire suite of test cases for the software application. This comprehensive approach ensures that all aspects of the software are thoroughly tested, but it can be time-consuming. Application monitoring tools are used to track bugs and issues such as slow response time, downtime, database deadlocks and poor code within companies’ applications and software.

2. Partial Regression Testing

Partial regression testing focuses on specific areas of the codebase that are most likely to be affected by recent changes. It offers a quicker testing cycle but may miss issues in untested parts of the application.

3. Unit Regression Testing

Unit regression testing involves testing individual units or components of the software in isolation. It helps catch regressions in isolated code segments.

How to Carry Out Regression Analysis?

For every organization, there are different regression testing methods. However, the majority generally adhere to the following key steps:

i. Identifying Source Code Modifications

The source code changes (modifications and optimizations are noted) are in this phase. Detecting modified components and their effect on the product’s core functionalities comes next.

B. Prioritize identified Adjustments and Product Needs

The test process is then synchronized with the necessary tools and test cases to prioritize all identified product needs and code updates.

C. Select Test Scenarios to Repeat

The biggest privilege of performance metrics and data insights is to get a direction for action. Saving time and energy from distraction, immediately act upon directions made by monitoring tools.

Fulfil all requirements for future growth, implement recommendations for improved performance and utilize resources and budgets as guided by application monitoring tools.

D. When Estimating Test Case Execution Time

To ascertain their influence on the test case execution time, test case factors include test data preparation, regression test designs, etc.

E. Sort Manual and Automated Test Cases

The test cases are divided into automatic and manual ones in this stage. Automated test cases run more quickly than manual instances handled by people. In the automated situation, the test code can also be used again. Thus, classifying test cases is an essential stage in the regression testing process.

F. Make Test Cases a Priority

The final step is to run each test case independently at the appropriate time to determine if the product works as expected. Automated or manual testing can be used here, depending on the needs and requirements. Automated technologies like Watir, IBM Rational Functional Tester, and Selenium can assist test case execution more quickly.

Techniques for Regression Testing

Regression testing is accomplished using the four fundamental implementation strategies of selecting regression tests, prioritizing test cases, retesting everything, and the hybrid approach.

i. Retest Everything

Regarding regression testing, the fundamental approach is to retest everything. This technique involves re-running all test cases, including those previously passed. Why? Because changes in the codebase, even seemingly unrelated ones, can have unforeseen consequences elsewhere. By retesting everything, you can catch unintended side effects and ensure that all existing features work as expected.

ii. Selection of Regression Tests

Not all test cases are created equal. Some are more critical than others regarding their impact on the software’s functionality. When selecting regression tests, it’s essential to prioritize. Focus on test cases that cover core functionalities, frequently used features, or areas where past issues have been identified. This ensures that the most crucial parts of the application are thoroughly tested after each change.

iii. Prioritization of Test Cases

Prioritizing test cases is an extension of the previous technique. It involves categorizing test cases based on their importance and potential impact. High-priority test cases, which cover critical functionalities, should be run first. Lower-priority cases can be executed later in the testing process. This approach optimizes testing time and resources while ensuring the most vital aspects are verified thoroughly.

iv. Hybrid Strategy

In some cases, a hybrid strategy may be the most effective. This method combines automated and manual testing approaches. Automation is excellent for repetitive and well-defined test cases, while manual testing allows for exploratory and ad-hoc testing. A hybrid strategy leverages the strengths of both methods, providing comprehensive coverage while saving time and effort.

Tools for Testing Regression

Every firm strives to provide a seamless user experience to its target population as applications get more sophisticated and complicated. Regression testing solutions are thus growing in popularity and are being used by several firms more frequently.

The automation, optimization, and simplification of the regression testing process depend heavily on testing tools. The top five tools for regression testing that are widely used in enterprises are as follows:

i. Selenium

Selenium is a well-established, open-source framework for automating web application testing. It supports multiple programming languages and browsers, making it a versatile choice for regression testing. Selenium allows testers to create robust and reusable test scripts, ensuring comprehensive coverage of web applications.

ii. Ranorex Studio

Ranorex Studio is an all-in-one test automation tool that simplifies regression testing for desktop, web, and mobile applications. Ranorex Studio empowers testers to create and execute test cases quickly and efficiently with its user-friendly interface and codeless automation capabilities.

iii. Katalon Studio

Katalon Studio is a powerful automation tool for end-to-end and regression testing. It provides many features, including test case management, scriptless automation, and integration with popular CI/CD tools. Katalon Studio streamlines the testing process, making it accessible to technical and non-technical team members.

iv. Test Complete

TestComplete is an automation tool that covers web, desktop, and mobile applications. It offers a script-free testing environment, making it suitable for testers with varying technical expertise. TestComplete’s ability to create automated UI tests and robust test scripts enhances the accuracy and efficiency of regression testing.

V. Sahi Pro

Sahi Pro is a cost-effective tool for web application testing. It excels in automating repetitive tasks and regression testing for web applications. Sahi Pro’s unique features include in-built reporting, parallel test execution, and a straightforward script editor. It’s a valuable addition to any testing toolkit.

Final Remarks - Regression Testing

We’ve explored the world of regression testing, from its definition and importance to its various types and best practices, by implementing effective regression testing strategies, software development teams can ensure that their applications remain robust and error-free throughout their lifecycle.

Regression testing is essential to verify that code changes do not affect the older or current product functionality and increase the end-user experience. Software faults are eliminated early in the software deployment cycle using the right regression testing tools.

By regularly conducting regression tests, developers can maintain the quality and reliability of their software, ultimately delivering a better user experience and saving time and resources in the long run. Don’t underestimate the power of regression testing in ensuring your software’s success in today’s competitive market.


Q1: How frequently should regression testing be carried out?

Regression testing should preferably be performed after each code modification or update to ensure software quality.

Q2: Do automated tools exist for regression testing?

Yes, there are several automation technologies, such as Selenium and JUnit, that improve the effectiveness of regression testing.

Q3: Why is regression testing done in the first place?

The main objective is to ensure new code modifications haven't adversely affected already-existing functionality.

Q4: Is manual regression testing possible?

While human regression testing is possible, for reasons of efficiency, automation is frequently preferable.

Q5: What distinguishes functional testing from regression testing?

Regression testing guarantees that all current features continue to perform as intended following modifications, whereas functional testing examines individual functionalities.

Q6: What common issues do regression tests run into?

Common difficulties include selecting the proper test cases, storing test data, and dealing with intricate application architectures.


Frank Fahad