What is Regression Testing and what are the Functions to be Tested?

Any technology, system, or software needs to be maintained and upgraded from time to time to ensure it functions at its optimal level. At the time of such maintenance and upgrades, developers may need to change the code or add new features. This is to ensure the software or technology solution performs well in its operating environment and offers a great interface with dependencies. However, the outcome of such technology upgrades may lead to system malfunctions or the ingress of bugs.

A simple code change in one part of the program may affect the performance of a feature or functionality in another part of the program. This may be in the form of reducing the page load time, increasing the utilization of system resources, or others. Software regression testing can help to mitigate such issues and ensure the upgrade works as intended. A case study related to the banking sector has shown that QA regression testing helps save around 60% of the time, which otherwise would have been spent on fixing bugs. Similarly, such testing can save around 40% in costs as well. Let us first understand what regression testing all is about and what functions are tested through it.

Why regression testing in software testing?

The need for conducting software regression testing arises when a change is made to a code or program for improvement or updation. This type of testing checks whether the new or modified code impacts other software components or modules and their execution. Also, regression testing helps to ensure the overall stability and responsiveness of the existing features. In the ultimate analysis, regression testing services are needed for bug fixing, adding new features, and fixing performance-related issues. It is arguably the final step in a long chain of testing processes that verifies the behavior of a software product in totality.

When should you conduct or apply regression testing?

The various scenarios to which regression testing is applied are as follows:

l An existing feature in a software application is updated with a new requirement

l A new feature is added

l Changes made to the code to fix defects

l Changes made to the source code to optimize performance

l Changes made to the product configuration

What are the challenges in QA regression testing?

This type of testing is not without its share of challenges, as mentioned below:

High cost: Manual regression testing can be very time-consuming and prone to errors. This type of testing is suitable for automation and needs an upfront investment in infrastructure and tools.

Testing approach: It is only by selecting the proper testing approach that any automated regression testing can be conducted successfully. This is irrespective of the fact that you have the best resources and tools to execute testing.

Scope and coverage: The successful outcome of any regression testing strategy would depend on the type and quality of the test suite. And the test suite should be updated between every build and deployment. The success of this exercise is underpinned by covering all the software elements, thereby making the ‘scope’ a challenge of sorts.

Complexity: The sheer number of test cases added to the regression testing framework can be mindboggling when moving from one build to another. Such an addition makes the test suite more complex as the testers need to test both the new and old cases.

How to perform regression testing?

Even though there is no fixed methodology or pattern for conducting software regression testing, the following pattern more or less sums up everything.

Identify changes in the source code: Find out the optimization and modifications done in the source code and identify the corresponding modules or components that have changed. Thereafter, find out the impact of such a modification on the existing features.

Prioritize changes and product requirements: The product requirements and modifications need to be prioritized for streamlining the testing process using the relevant test cases and tools.

Determine criteria for entry: Be assured if the application meets all eligibility criteria before executing regression testing.

Determine exit point: Select a final point for the eligibility or conditions, identify all test components, and schedule an appropriate execution time.

Conclusion

Regression testing is an important milestone in the suite of software testing that aims at improving the overall quality of the software product, besides the user experience. It can help identify most defects and fix them early in the development and delivery pipeline. By implementing various types of regression testing, namely, corrective, progressive, selective, partial, complete, and retest-all, the updating and improvement of any software application is not a challenge anymore. Further, by making investments in planning and implementing regression testing, businesses can exercise more control over their budget and error mitigation process.