Regression testing has primarily three predominant implementation and deployment methods, including the re-test all strategy, the regression test selection strategy, and the test case prioritization strategy.
In this first technique, regression testing is thoroughly deployed applying to all existing test suites. It is the safest way to ensure all bugs are detected and resolved, even though this method is both time and resource intensive.
The complete regression approach fits better in certain contexts as It’s best when an application is readjusted for a new platform or language, or when the operating system gets a major update.
Regression Test Selection
Selecting the relevant sections that can be affected by changes and deploying regression testing on the selected parts only. Mapping out co-related areas can help apply limited and relevant test cases to significantly reduce both the time and effort invested in a regression execution.
Test Case Prioritization
Prioritize test cases to be included and tested first in the regression process. These test cases should be prioritized on these criteria: failure rates, business impacts, and end user POV including gradually used functionalities.
The test cases directly relating to customer-facing aspects and newly added functionalities are considered high priority as well.
Regression in Agile
Within the Agile development approach, teams proliferate additional benefits and values, such as an accelerated time-to-market, ROI, customer support, and product improvements. This comes with a significant challenge of perfectly balancing sprint development cycles and executing iterative testing avoiding conflicts as the product stabilizes and matures.
Successful Agile implementation of regression plays a key role in fully aligning the existing and updated functionalities, avoiding all possibilities of rework in the near future. Agile regression testing ensures all the basic business functions are stable and sustainable.
Alternatively, regression helps developers to focus all efforts on building new features/functionalities for the application and then keep on returning to cross-checking defects in the old features.
Successfully applying regression reveals the unexpected risks in all software builds, helping developers to respond and refix more quickly and efficiently.