Maria Homann
Testing is an integral part of developing quality software. Regression testing is a very important part of testing, but it's also one of the most time-consuming and error-prone.
In this guide, we take you through the best practices for regression testing that you can follow to alleviate the regression testing burden and enhance quality. This will help you and your QA team ensure high test coverage with every release, no matter how frequent. We'll also explore the power of automation - when done right - and the impact it can have on overall speed and quality.
Skip ahead to:
Top 9 regression testing best practices
The benefits of following regression testing best practices
Continue learning about regression testing
Make sure to check out these additional resources on regression testing as well:
➡️ Webinar: Automate to Innovate: Mastering Regression Testing with Leapwork
➡️ Whitepaper: How to do Regression Testing in Agile Teams
What is regression testing?
Regression testing is a vital component in the testing lifecycle, whether you're checking simple web applications or complex, business-critical workflows. Regression testing safeguards your applications and processes against bugs as they evolve over time.
Every software update requires testing to ensure that things don't break. You can distinguish between two sides of testing:
- Testing new features
- Testing existing functionality
Regression testing focuses on the latter.
It might seem less important than testing what's new, because it somehow seems less likely that existing things will break. But that's a misconception. There's always a risk that new code can impact existing code. Many of the most critical functions lie in the things that are already there, and when left untested you're exposing those processes to risk.
We've compiled a list of nine best practices for successful regression testing that you can follow to enhance your testing strategy.
Top 9 regression testing best practices
1. Set goals and measure success
Your motivation for reading this article is probably to improve your regression testing initiatives. But how will you prove progress if you don't have a starting point and an end goal?
Make sure to set up key performance indicators through metrics such as:
- Test coverage
- Bugs entering production
- Speed of testing
- Speed of releases
With a clear destination, there's a greater chance you'll stay focused on initiatives that will truly move the needle.
Here are a couple of organizations that have transformed their regression testing strategy with clear goals and great outcomes:
➡️ Specialist bank, Investec, automated 95% of their regression suite to reduce risk across the organization and deliver 3x faster time to market.
➡️ JF Hillebrand, a logistics company, fully automated its regression testing of web apps in three months. Through automation, they reduced testing time from 3 days to 40 minutes, a 97% reduction.
2. Prioritize test cases
You can't test everything everywhere all at once. And you shouldn't - that would only give you vast amounts of test results that your team probably wouldn't be equipped to handle.
This goes both for manually testing regression testing and for automated regression testing, where you need to decide what to build first.
Instead, prioritize the test cases based on:
- How critical the features or processes you're testing are
- How likely changes are to impact your tests
- How customers are using your software
- Whether there's a history of bugs
3. Automate where possible
"But we don't have time to test everything, every time!"
Few teams do, if they decide to test manually. Automation is the only way to keep up. Not everything should be automated, but regression tests are ideal candidates for automation because they are:
- Highly repetitive in nature: Regression tests are run repeatedly throughout the software development lifecycle (if best practices are followed) to ensure that new changes do not break existing functionality. Automation is ideal for such repetitive tasks, eliminating the need for manual execution every time the codebase is updated.
- Predictable: Regression tests often target stable parts of the application where changes are less frequent, making these tests less likely to require frequent updates. This stability makes them perfect for automation, as automated tests perform best when the test target is predictable and does not change often. Regression tests are also usually well-defined with expected outcomes based on the previously established functionality. This clarity makes them straightforward to automate, as there is a clear criterion for passing or failing the test.
- High in volume: The number of regression test cases grows over time, as the software evolves. Automating these tests allows teams to manage and execute a high volume of tests efficiently, which would be impractical to perform manually within tight timelines.
Automation alleviates teams from these repetitive tests, helps avoid human error that is prone to happen when testing repetitive things manually, and frees up time to focus on other core areas of the testing strategy that require a human's critical and creative thinking, such as exploratory testing.
So how do you get started with automation?
Some tools have no license costs, whilst some will require a budget to get started. Remember however that free tools that require developers aren't free. And regression testing in particular tends to become a bit of a bottleneck if you're dependent on developers to update your tests. So seeking a budget for a tool might be worth it from the get-go.
Here are 2 resources that might be useful if you choose to go in this direction:
➡️ How to Do a Test Automation Tool Evaluation
➡️ How to Calculate the ROI of Test Automation
4. Keep maintenance in mind
Every application and every IT landscape that that application is a part of will evolve over time. Either through changes you make, because you're developing the software or creating customizations, or because it's a packaged application and those developing it are pushing out service releases or updates.
So maintenance is a must. You can minimize the maintenance of automated tests by considering two main strategies:
- Stability: Use reliable methods and stable identifiers from the start. Choose automation tools wisely, ensuring they handle expected changes well for the technologies you are using. Proper test data and stable environments are also essential to avoid failures unrelated to application issues.
- Ease of updating: Embrace modularity and reuse in test design. Instead of updating tests individually with every development change, ensure that the testing tool you are using allows you to create centrally updatable modules. This allows for quick adjustments when business processes evolve.
Effective test case design is key, emphasizing a "less is more" approach to ensure clarity and ease of maintenance. These two considerations will help you in quickly updating tests as the application changes, reducing both short-term and long-term workload.
Learn more in our whitepaper: How to create maintainable and scalable test automation.
5. Leverage test management tools
Keeping track of test progress and results is as important as creating the tests in the first place. Finding a good test management tool, ideally one that integrates with your test automation platform, will help you in managing your tests and reporting on bugs.
6. Integrate into your CI/CD pipeline
Fast feedback on tests can help speed up the entire development process. By incorporating continuous, automated regression testing early in your CI/CD pipeline, development can receive immediate feedback on new code, ensuring faulty code doesn't pass down further into the pipeline.
For further reading on continuous testing, make sure to get our guide: Continuous testing in Agile
7. Select appropriate test cases for regression
Even though automation makes it possible to run all tests at every release, you still want to think about the results you're getting from your tests, and which of those are most important for you to analyze.
For that reason, it can be useful to prioritize your tests in the following way:
- Functionality with direct impact: Test the functionality that is directly associated to and can be affected by the changes.
- Functionality with indirect impact: Test the functionality or processes where there's a risk of indirect impact.
8. Enable cross-functional collaboration
Different people see different things. Developers will view regression tests one way, functional testers another, and business domain experts a third. It's useful to involve several perspectives - not to have too many chefs in the kitchen, but to avoid bias and blind spots.
A simple way to enhance cross-functional collaboration in testing is to ensure that the automation tool you're using is easy to understand and in 'plain English'. If it's code-based or overly complex, you'll prohibit potentially important input from stakeholders.
9. Create standards and follow them
To streamline test automation efforts, it's essential to establish common standards. Work with your testing team to identify universal test components and agree on documentation and naming conventions. This approach prevents the redundancy of components within your regression test suite, maximizing re-usability.
Maintain a document outlining these standards and update it as your team discovers more efficient testing methods. This living document serves as a guideline for current and future testing practices.
Additionally, implement an error handling process that logs and reports issues. This system allows for the swift identification and resolution of problems, contributing to a smoother user experience. Utilize tools equipped with visual debugging features to pinpoint the exact moment and cause of test failures, enhancing your debugging efficiency.
The benefits of following regression testing best practices
When properly executed, an effective regression testing approach that follows best practices can help teams achieve several key outcomes:
- Elevated software quality by minimizing bugs and issues in the production environment.
- Increased user satisfaction, resulting from a smooth and dependable user experience.
- Faster time-to-market due to the early detection and fixing of bugs.
- Streamlined resource utilization and reduced expenses, thanks to low maintenance and optimized testing workflows.
- A unified team atmosphere dedicated to the consistent delivery of superior software solutions.
- Enhanced confidence in software releases among quality assurance personnel.
Continue learning about regression testing
There's plenty more to learn about regression testing strategy. Watch our on-demand webinar on automated regression testing to learn how you can take regression testing to the next level and enhance software quality in your organization.
