This guide discusses the keys to effective regression testing including planning, building effective test suites, and selecting the types of testing to execute.
Regression testing—so much to cover, so important to plan for, yet typically within a tight time window. Regression test execution changes rapidly. The style and type that’s executed must fit into short timelines and provide as thorough test coverage as possible. Regression testing must be lean, aggressive, effective and efficient. Effective QA teams plan regression testing efforts that locate defects before the customer finds them.
One can think of regression testing as a game of chess, but at a higher speed. What’s the most effective means of regression testing? How does an application development team continue to create and release quality code at a rapid pace to keep up with customer and business demands?
This guide discusses the keys to effective regression testing from planning an approach, building a regression test suite and selecting the types of testing appropriate for the timeline for test execution.
Software maintenance includes providing a continuous stream of new features, feature enhancements and bug fixes. Making modifications to an existing codebase typically results in also creating new, unexpected defects. Regression testing provides verification that the application remains functional and working as expected for customers.
Effective regression testing improves application quality at the release point and ensures customers are not negatively impacted by a new release. Granted, the quality of the regression testing effort directly impacts the quality of the customers’ experience with the new release.
Think of it this way, without regression testing a software application and team typically find themselves drowning in massive amounts of tech debt or defect reports and negative customer experience ratings. Consistently defective releases break customers’ trust in the application. Once trust leaves, it’s difficult or impossible to repair. Invest in regression testing to ensure a consistent, quality application experience for customers.
Planning is critical for creating effective and efficient regression test execution. As a QA tester within a team or on their own, planning out the regression testing approach, tests and tasks makes a difference in test coverage. Without planning, testing becomes random based on the interest and knowledge of the individual tester and often results in duplicated work. In other words, planning eliminates duplicating work instead of testing additional features. Testers duplicate work when selecting the same test for execution or within the same feature repeatedly.
It happens easily, especially on larger QA teams that include internal and external team members. Communication and planning are key to keeping teams organized and focused on regression testing in their areas for defects. Planning test execution ensures test coverage and keeps team members from having to figure out what to test and where. The more focused the team is on testing, the greater the team’s test coverage. Planning regression test execution improves tester focus and eliminates duplicate work to gain greater breadth and depth for test coverage.
Regression test planning includes:
Consider tools for managing test automation as part of regression testing efforts. Codeless testing tools like Test Studio leverage AI/ML technology to detect code changes in the user interface and automatically update test scripts. Test maintenance needs are reduced as is the need to re-create recorded scripts.
Regression testing includes several possible options. What type of regression testing is selected depends on the application, the team and the time allotted for testing. When planning regression test execution, determine the general type of regression testing to perform.
Regression testing general types:
Complete regression means testing everything, or all the test scripts associated with the application. Executing a complete regression even for a simple application is time-consuming. For a complex or distributed application, complete regression testing is not feasible due to time and the ability to create or simulate all active connections and integration points to mimic the production or live server.
Selected regression means narrowing down the scope to include testing all application areas, but not necessarily all test scripts. For example, if the bug fixes and enhancements occur in specific areas then tests may be executed against that area only. Or QA test teams may create rotating test suites made up of test scripts that cover specific areas. Only one rotating test suite gets executed during regression, but that suite still covers the application’s functionality.
Regression testing by priority means creating test suites based on the test cases priority, or the priority associated with the functionality. Most defects and new features get assigned an initial priority based on how critical they are to the application functionality. With priority regression, regression tests are built in sections and executed in priority order. For example, the critical test suite gets executed first, followed by the high, then medium and then the low. Priority regression ensures the most critical test cases are tested first.
Progressive regression testing tests the impact of a new component on a system. Progressive regression testing requires testers to know and understand the nature of each code change. Tests are executed based solely on the changes to the code.
Defect regression testing means re-testing each defect within the release code. Defect testing ensures the same defects do not exist in the new release. Retesting only defects may or may not find issues within the application as a whole. However, defect regression testing does ensure the same defects do not appear in the new release.
Continuous regression testing means the QA team tests through the complete set of regression test suites repeatedly on an ongoing basis. By using continuous regression testing, the need to designate time for regression testing is eliminated. Regression testing continues on a regular cadence without interruption. Tests may be executed by separate teams or divided and assigned among testers.
QA testing teams using continuous testing regression often mix regression testing tasks with new features or story testing as time allows. The key to successful continuous regression is team buy-in and consistent action by finding defects with every build.
Selecting regression tests and building test suites takes both skill and creativity. Once the type of regression testing is known, the team and time are defined then it’s time to build out the best regression testing suites. When creating regression testing suites remember the goals of regression testing:
When building regression testing suites, make sure all application functions are covered. Additionally, integration and backend testing are critical for regression testing. Bugs tend to show up in an application when the integrated functions are used. Integrated functions include APIs, database connections, backend messaging systems and third-party software built into the code. Third-party software is often used to handle notification processing for emails, SMS or fax.
Select tests in areas with frequent defects or that are known to be fragile. Additionally, choose tests that customers use more frequently. Always include tests for critical functionality the application cannot function without.
QA testing teams or regression suite builders can use a popular and useful mnemonic named RCRCRC.
RCRCRC stands for:
Regression testing properly planned and executed is both effective and valuable. Regression testing improves business value by ensuring a positive customer experience for each application release. Regardless of whether regression tests are automated or manual scripts, planning test coverage is essential due to the necessary test coverage and time constraints.
Solid regression test planning is critical to constructing effective test suites and keeping tester’s focus on finding defects in their assigned areas first. Managing regression testing requires planning and test suite-building skills. The types of regression test suites created, and the tests included must cover the bulk of the application functionality. Regression testing efforts are often limited by time and testing resources. Selecting the correct type of regression testing for the application is essential. Organize effective regression by selecting from a variety of regression test suite options and regression test types.
Consider using a testing tool like Test Studio for managing test automation as part of regression testing efforts. Such a tool can automatically detect code changes and update test scripts, reducing maintenance costs and improving test quality.
A QA test professional with 23+ years of QA testing experience within a variety of software development teams, Amy Reichert has extensive experience in QA process development & planning, team leadership/management, and QA project management. She has worked on multiple types of software development methodologies including waterfall, agile, scrum, kanban and customized combinations. Amy enjoys continuing to improve her software testing craft by researching and writing on a variety of related topics. In her spare time, she enjoys gardening, cat management and the outdoors.
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