How can you design and execute regression testing to detect software defects?

Regression test is basically done to make sure existing software is not broken due to the new changes introduced to the software. Having robust regression suite for critical modules is highly important. In my opinion, regression test results should be considered when making go/no-go decision for the new release.

Regression testing addresses a common issue that developers face emergence of old bugs with the introduction of new changes, whenever the code is changed, and you need to determine whether the modified code will affect other parts of the software application. Moreover, regression testing is needed when a new feature is added to the software application. Regression tests may also be performed when a functional or performance defect/issue is fixed.

Regression testing is software testing if anything is modified in features or changes any functionality, so after fixes we have to make sure that all existing things work properly with the new fixes.

Regression tests shall not be run blindly by executing the entire regression test suite each time. It can be time and effort consuming. A better approach is a targeted regression test based on analysis of the impact and nature of changes. Determining potential targets for regression testing in this way can also save time and expedite the entire process, when all test evidences need to be gathered and approved for the final verification of the software as medical device and composing a submission dossier to FDA/EU-MDR. Using a general method to determine a change impact and find targets for regression testing is also much valued by auditors, because it shows them that the project is in control of risks that are associated with each change.

Regression testing is a technique through which the verification is done whether the product/application is intact or not. It is important that in Agile, with every release of a new feature, it is verified that it's not halting the current stable version.

Regression testing is important because the integrity of the stable application should not break when a layer of new enhancement is added to that.

Performing regression testing is pivotal with every deployment. This ensures that the introduction of new features doesn't lead to any new issues in the application. It's also a way to double-check that the build remains stable. Remember, it's essential to fine-tune these regression tests after each new functionality is added.

Regression testing is crucial because it safeguards the integrity and reliability of software as it undergoes updates and enhancements. By systematically retesting previously validated functionality, it detects and prevents the introduction of unintended defects and ensures that existing features continue to work as expected. By catching issues early and consistently, regression testing saves time and resources, boosts confidence in software quality, and ultimately delivers a smoother user experience. It's a fundamental practice for maintaining software integrity and supporting agile development processes.

Regression testing is important because it echos the stability of the software product irrespective of minor/major the enhancements/fixes. More stable product means more reliable the business is and hence the product gets better customer satisfaction. A better regression suite will always helps in this matter. We should also keen to maintain the regression suite by adding/removing scenarios as enhancements go. One should also make it run on regular intervals which would definitely helps mitigating the failures due to different runtime failures.

Regression testing is important because it helps ensure that software changes and updates do not introduce new defects or negatively impact existing functionalities. It prevents the need for extensive rework and debugging in later stages, which could potentially delay release schedules and increase costs. Overall, regression testing is crucial as it helps maintain software integrity, stability, and quality throughout its lifecycle, providing a reliable and satisfactory user experience.

Also, update your regression test suites based on the Production issues that are being reported by the end users. It will help us identify the issues which are more likely not replicable easily during the testing phase due to certain limitations but can leave a negative impact on consumer satisfaction.

While designing an efficient and effective regression test it is good to ask the question: If this part of the software changes, is it clear which tests need to be run to clarify that there are no residual risks left?+Regression testing is a part of the safety net, so if important defect was not catch and appears in the production, a gap in this safety net needs to be analysed. It is also about having a good balance between severity of issues to be catch and the time spent. It is also a good idea to distinguish different levels of priority in the regression test. In this case regression tests with highest (red) priority (to catch the most important issues) will be always executed before going to the production while balancing the rest.

Regression testing should be carefully designed to maximize its effectiveness and efficiency. It begins by identifying a suite of TCs that cover critical functionality, edge cases, and scenarios prone to change. Automation is key for repetitive execution, allowing for quick feedback during development. Prioritize TCs based on their impact and likelihood of change to optimize resource allocation. Maintain version control for TCs to track changes and ensure alignment with code updates. Integrating TCs into the CI/CD pipeline streamlines the process, ensuring that tests are run automatically whenever new code is committed. Test suite should be periodically reviewed and updated to adapt to evolving software requirements and minimize redundancy.

Make sure that your regression test suite contains many types of testing. Let's start with simple e2e user journeys and expand the automation coverage into smaller pieces. The non-functional requirements should also be under consideration when creating a test suite. It's also worth remembering to update it not only when we're adding the new feature but, for example, based on the main user journeys in the app. Having decent analytics implemented could help.

There are many things to consider when it comes to design a proper regression testing suite: -Automate. This is a "must" nowadays, manual regression is very unefficient and also demotivates the manual QA team. -Don't add hundreds of test cases to the regression. This is a common mistake. The regression should have only the most critical end to end test cases. Otherwise, it becomes huge and impossible to run frequently or on each deployment. -Include your regression into a CI pipeline. This is also something you need to do ASAP. The final step of each deployment should be the regression. -Choose your framework wisely. Try different frameworks and choose the one that fits your company the most. Don't follow "trends".

By best practice regression testing is done when the application/system under test reaches a stable point where test cases/test suites can be executed multiple times. With this in mind you can do regression testing either manually or automated. Automation is actually the best choice for regression testing, given that it can be done unmanned and it's a time saver. And since regression testing is done to check for any flaws or issues from existing and working functionalities, it is crucial that your tests can cover as many scenarios as possible with lesser number of tests to run (in other words testing things smartly not exhaustively). There are testing techniques (such as All-Pairs, boundary value, etc.) that can be used to achieve it.

When test cases are written, regression testing execution occurs either regularly (at the end of each sprint, every quarter, ...) and/or at critical moments of the software development life cycle (for instance as a validation gate, before releases). Regression testing is commonly done manually at first, a team of QA engineers then executing the test cases by hand. As this task is time-consuming and repeated many times in the lifespan of the software, it is however recommended to then automate these tests as early as possible, through your test automation tool of choice (Cypress, PlayWright, Microsoft Power Automate, ...). This way, the QA engineer team can use the time gained for more added-value activities, such as exploratory testing.

Regression testing is done by comparing the result from previous version of application with the current version. Complete regression suite must be divided into several functional areas to ensure that even with small code changes we have scope to identify and run a sub set of regression.

While doing automation there is a functionality to group the test cases.Just set the priority for the test case and group those test cases and run this regression suite based on the need.In manual testing it’s a time consuming process and we need to make sure that each and every test case in the regression suite is working fine.

Since in most of the cases regression testing finds most number of bugs in comparision to any other change request being tested on the given software version, lesson learnt from regression goes long way in maintaining the integrity and stability under acceptable terms for the software application.

After running the test suite, generate a detailed report, including test case outcomes (pass or fail), along with steps to reproduce any issues. Analyze findings rigorously to identify root causes of failures, whether they result from code changes, configuration settings, or other factors. Prioritize issues based on severity, considering their impact on software functionality. Collaborate closely with the development team to resolve problems promptly. Communicate findings to stakeholders for transparency. Maintain a historical record of regression test reports to track quality trends over time, enabling data-driven decisions for releases and continuous improvement. This process ensures software reliability and an enhanced user experience.

Updation as well as Sanitization of Regression suites also plays an important role in STLC : 1. With every new application changes in a release, one should also consider updating the mandatory/required test cases in the regression suites. It will help in improving the test case coverage. 2. Removal of unwanted test cases or fixing of failed / flapper test cases in a regression suite also helps in determining the correct testing estimations and stability of builds, one should keep track of it in every release for a good and healthy test suites.