The role of automated regression testing in the software development life cycle (SDLC)

What is regression testing?

Regression testing refers to the process of testing software after changes are made to the codebase. These changes can be due to many reasons, such as software getting new functionality/feature additions, modifications to existing features, and the countless bugs that can arise during the production phase.

Manual vs automated regression testing

Manual regression testing, as the name suggests, is manually executing the regression tests one after another. Though time-consuming, it can be precise at identifying the problem, especially if the number of test cases is smaller in number.

Automated regression testing focuses on automating these regression tests. If the number of test cases is large, automated regression testing is the way to go. It can be very effective at running regression tests efficiently, over and over again, thereby saving resources and reducing maintenance.

Thankfully, not all regression tests require the creation of new test cases. In such cases, a regression suite can easily be created with the existing test cases, irrespective of whether it's used for manual or automated regression testing.

Why automated regression testing is important 

Automated regression testing helps in uncovering bugs and errors during the different stages of the SDLC, especially in an agile software development environment, which is prone to frequent changes and bug fixes within each sprint. Identifying and fixing the bugs before the software is pushed to the production phase can save the QA team a great deal of the time and resources required to handle the same errors at a later stage.

Under adverse situations, automated regression tests can help the QA team perform damage control by informing the development team that they need to regress back to the previous build of the software.

How automation enhances regression testing

Regression testing is most efficient when coupled with automation to uncover high priority bugs which are missed during other types of testing. Automated regression testing can be scheduled to run at regular intervals, thereby eliminating the need to wait for manual testing, especially if testing is warranted beyond working hours. Certain regression tests need to be performed in succession for efficient testing; automation is the key in such scenarios.

There are different types of regression testing based on the software testing requirements, and a thorough understanding of each type can help in choosing the right one for the project at a given time. They are:

• Unit regression testing - Unit regression testing is performed as part of the unit testing phase on individual code units, without taking into account the various dependencies and integrations with other parts of the software. Focusing on just a unit of code increases efficiency and greatly reduces the possibility of errors.
• Partial regression testing - After testing the code of individual modules to ensure that they perform as intended on their own, partial regression testing is performed when these chunks of code are integrated into the existing code. Since existing test cases are used and the scope does not extend to the entirety of the software, testing takes up less time.
• Corrective regression testing - Corrective regression testing is performed at regular intervals when no new changes are introduced to the project specifications. Existing test cases can be used to check if everything works as intended.
• Progressive regression testing - Unlike the previous testing type, most of the time there are changes to the product specifications, which render preexisting test cases useless. Progressive regression testing is effective in such scenarios, since new test cases are created to check how the changes affect the overall software.
• Selective regression testing - Certain software modules are prone to frequent changes or modifications. Selective regression testing is used to test those particular modules and their dependencies, using a mix of existing test cases and new ones. This helps in mitigating errors that can arise owing to frequent changes.
• Retest-all regression testing - This type of regression testing is the most complex and time-consuming one of all. In rare circumstances, when the QA team is unable to locate the cause of a major error and suspects inefficient testing in the previous stages, they resort to retest-all regression testing. As the name suggests, it involves checking every small change made to the software from the beginning. This testing is not recommended for minor modifications to the software.
• Complete regression testing - Complete regression testing is performed before making software available to the end user. Whenever changes have a great impact on the source code, performing other types of regression testing will not be efficient at identifying errors which may affect the overall stability and performance of the software.

All of the above discussed regression testing techniques, coupled with automation can optimize the testing phase.

Automated regression testing with Zoho QEngine

Creating, managing, and executing test cases is the most important part of performing regression tests efficiently. Zoho QEngine gives users the flexibility to create test cases using no-code, low-code, and pro-code options. The results dashboard in Zoho QEngine provides detailed reports of test case executions to help the development team work on fixes.

Automation ensures that the regression testing is carried out efficiently, since repeated execution of the test cases is essential for their success. Automating the test cases on Zoho QEngine using its test case modules, plans, and suites is very simple, as well as efficient. Check out how to perform regression testing on Zoho QEngine here.

Conclusion

Planning and executing regression tests, from start to finish, can be daunting for QA teams, especially if the project has multiple dependencies with other functionalities. When carried out efficiently, automated regression testing is the key to ensuring that the software is devoid of errors associated with its compatibility, stability, and performance.