The frequent changes in requirements and the rapid pace of development in Agile underscore the critical need for regression testing. However, if not done right, regression testing can pose challenges for agile teams, potentially impeding delivery speed and interrupting release timelines.
What’s the role of regression testing in Agile?
In agile development, regression testing protects existing software functionalities from negative effects caused by new code changes or additions.
In regression testing, testers verify that the updated code base (the code base after changes have been merged) is passing all desired and expected functionality. The main goal is to avoid introducing new bugs while ensuring that existing functionalities remain intact.
The significance of agile regression testing lies in its contribution to maintaining software quality and stability during iterative development cycles, aligning with Agile methodology principles, and facilitating efficient and dependable software development processes.
How to choose an agile regression testing strategy
Determining the right regression testing strategy for your team involves considering various factors like team size, sprint duration, and preferred testing methods. Teams must also decide whether to employ scripted manual tests, automated tests, unscripted exploratory tests, or a hybrid approach.
Here are the top 5 considerations when determining a regression testing strategy:
Understand project requirements:
- Identify critical functionalities and areas prone to frequent changes
- Determine the scope and goals of the project to understand your software testing needs
Assess application characteristics:
- Understand the complexity of the application and its critical paths
- Identify high-risk areas and components prone to regression
Evaluate team size, skills, and resources:
- Assess the team’s expertise in test automation, manual testing, and other methodologies
- Consider available tools and resources for testing
Analyze risks and impact:
- Identify potential risks associated with changes being made
- Evaluate the impact of a regression issue on the user experience and system stability
- Prioritize testing features based on their level of risk and potential impact on the software system. Focus more on high-impact or critical functionalities to ensure thorough validation and reduce the likelihood of critical issues.
Prioritize and plan test coverage:
- Prioritize test cases based on criticality and frequency of use
- Find the right balance between breadth (wide scenario coverage) and depth (thoroughly testing critical functionalities)
When to regression test in Agile
Regression testing is a continuous process conducted across the development lifecycle. Its frequency is determined by the specific practices and methodologies adopted by agile teams. The ultimate goal is to detect and address regressions as early as possible in the development lifecycle, preserving the software’s reliability as it changes.
Typical scenarios warranting regression tests involve:
- After committing new code
- At the initiation and conclusion of each iteration or sprint cycle
- Before a release or production deployment
- After critical bug fixes or emergency patch releases
- Following substantial code refactoring or platform updates
For example, let’s say you’re testing a tax program that calculates which deductions a business can take and what each deduction is worth.
Imagine the development team introduces a significant change altering the application’s tax calculation process. Regression testing becomes necessary as this change impacts the expected workflow of tax calculations, requiring confirmation that it doesn’t introduce defects within the existing codebase.
How to build and implement an agile regression testing strategy
Creating a regression testing strategy involves several steps to ensure comprehensive coverage while adapting to agile principles. Here’s a structured approach:
|1. Understand project context
|–Scope identification: Determine critical functionalities and high-risk areas
-Requirements analysis: Understand project goals and user needs
|2. Define regression testing objectives
|-Establish clear testing objectives (stability, impact analysis)
-Identify testable items (features, integrations, interfaces)
|3. Assess testing resources and tools
|-Evaluate team skills and available testing resources
-Choose appropriate testing tools aligned with Agile practices and project needs
|4. Prioritize test cases
|-Assess criticality based on business impact and recent changes
-Prioritize tests covering core functionalities and susceptible areas
|5. Define regression testing methods
|-Implement continuous integration for ongoing validation
-Use automated regression testing for repetitive and critical test scenarios
-Plan for manual testing when necessary
|6. Create a test suite
|-Develop/update a comprehensive suite covering prioritized functionalities
-Ensure modularity, reusability, and maintainability of test cases
|7. Establish testing environments
|-Set up stable, consistent testing environments mirroring production
-Manage test data effectively for consistency and integrity
|8. Define regression test execution plan
|-Determine test execution frequency (after sprints, before releases)Establish reporting mechanisms for tracking results and identifying issues
|9. Collaboration and communication
|-Encourage team collaboration among developers, testers, and stakeholders
-Maintain regular communication about testing plans, progress, and discovered issues
|10. Regular review and iteration
|-Continuously review and refine the strategy based on feedback, results, and evolving project needs
Common regression testing types
While defining regression testing methods, one crucial aspect is deciding which types of regression tests are most suitable for the project’s needs.
This decision-making process directly influences the creation of the test suite, as it guides which specific tests will be developed or selected to cover different aspects of the application affected by changes.
There are several different approaches to regression testing, depending on the changes that were made to your application’s code and the available time and resources in your sprint.
Here are some commonly used regression testing types:
|Regression Testing Type
|Complete regression testing
|Execute the entire suite of regression test cases to ensure comprehensive coverage of the application
|Critical releases or major updates requiring thorough validation
|Partial regression testing
|Execute a subset of test cases based on the areas affected by recent code changes
|Projects with time constraints or testing focused on specific impacted functionalities
|Selective regression testing
|Choose and run specific test cases strategically selected based on risk analysis and impact
|Projects with limited time or resources, emphasizing high-priority functionalities
It’s important to note that crafting a robust regression testing strategy often involves blending various options to suit the specific context.
Using these regression testing types effectively in Agile requires creating test plans that incorporate them into the ongoing development process. This means crafting test plans that specifically address these different test types within the iterative testing cycles of Agile development.
How to construct test plans for regression testing in Agile
Constructing test plans for regression testing in Agile involves several steps to ensure comprehensive coverage and adaptability to Agile principles:
- Identify objectives: Clarify testing goals and prioritize what needs to be tested based on changes and critical functionalities
- Select the right tests: Determine specific regression test types required for the project’s context and changes made
- Create a comprehensive test suite: Develop modular, reusable test cases covering critical functionalities and impacted areas
- Establish testing environment: Set up stable environments mirroring production and manage test data effectively
- Plan test execution: Define when and how regression tests will be executed, integrating continuous testing where possible
- Encourage collaboration: Foster teamwork and maintain open communication channels among team members
- Continuous refinement: Regularly review and adapt the regression test plan based on feedback and evolving project needs
How to implement regression testing in Agile
In simpler terms, sprint-level tests catch quick problems, like after each sprint, while end-to-end tests check everything’s okay before big releases. Both help improve the strategy by giving feedback and helping it to get better over time.
Successfully implementing regression testing in Agile means integrating it seamlessly into the development lifecycle while adapting to the iterative nature of Agile. Multiple approaches facilitate this integration
Continuous integration (CI):
- Approach: Incorporate regression tests into the CI pipeline
- Benefits: Automate tests to run whenever new code is added
- Purpose: Detect regressions early in the development cycle
CI involves regularly integrating code changes into a shared repository. While it’s not a test itself, CI often triggers automated tests, including unit tests or smaller integration tests, making it more aligned with sprint-level testing.
- Approach: Automate repetitive regression test cases (i.e. smoke tests, unit test regression, integration tests, data-driven tests, end-to-end regression tests, browser/platform compatibility tests.)
- Benefits: Speed up testing, ensure consistent test execution
- Purpose: Efficiently validate core functionalities across iterations
Test automation covers a broad spectrum of tests and can include both sprint-level and end-to-end tests. It depends on the specific tests automated within the process. Unit tests and some integration tests might align more with sprint-level testing, while comprehensive end-to-end tests fall under end-to-end testing.
Selective test suites:
- Approach: Prioritize and maintain a subset of critical regression tests
- Benefits: Focus on high-impact areas or features prone to changes
- Purpose: Optimize testing efforts without compromising coverage
These suites generally comprise a selection of tests chosen strategically based on factors like critical functionalities or areas prone to frequent changes. They can encompass both sprint-level tests and specific end-to-end tests, depending on the criteria for selection.
Parallel test execution:
- Approach: Execute regression tests concurrently
- Benefits: Reduce testing time by running tests simultaneously
- Purpose: Expedite testing, especially for extensive suites
This is a method of running tests concurrently, allowing for faster execution. It’s a technique that can be applied to both sprint-level and end-to-end tests to expedite the testing process but isn’t inherently tied to a specific type of test.
- Approach: Assess and prioritize tests based on potential risks
- Benefits: Focus testing efforts on areas with higher risk exposure
- Purpose: Optimize resource allocation for regression testing
This approach involves prioritizing tests based on the perceived risks associated with different features or functionalities. It can encompass both sprint-level and end-to-end tests, as risk assessment applies to various levels of testing based on the impact of potential failures.
Considerations for implementing test automation for regression testing
Automation remains crucial irrespective of the testing approach employed due to its inherent advantages. In any approach—be it Agile, Waterfall, or others—automation ensures swift execution of repetitive tasks, maintains consistency, expands test coverage, speeds up regression testing, cuts costs, and provides rapid feedback.
These benefits hold regardless of the methodology, underlining the universal significance of automation in enhancing testing efficiency and reliability across all approaches.
Choose what to automate
Assess which tests are suitable for automation. Automate repetitive and critical test scenarios that provide maximum coverage and value. Your team should develop specific guidelines for deciding what to test with automated testing tools and what to test manually. Determining the scope of automation is sometimes called an Automation Feasibility Analysis.
Regression testing within Agile
Ensure test cases remain relevant and aligned with the evolving project requirements and functionalities. Maintain version control for test scripts to track changes and updates.
Determine the frequency of regression testing based on project needs, release, and sprint schedules. It’s important to find a balance between testing frequently enough to catch regressions and not impeding development speed.
Collaborate between testers, developers, and product owners to define regression testing strategies. Maintain clear communication about testing objectives, progress, and discovered issues across the team.
By adopting these approaches, teams can effectively embed regression testing into agile workflows, ensuring stability and facilitating iterative development without compromising quality.
Common regression testing challenges
Agile regression testing presents challenges, demanding time and ongoing refinement to establish an efficient strategy balancing testing speed and comprehensive coverage. Below is a chart summarizing common agile regression testing challenges and their mitigation strategies:
|Regression testing challenges
|Prioritize and automate critical testsRegularly update test cases
|Prioritize tests based on risk and impactLeverage test automation and parallel testing
|Test data management
|Invest in test data generation toolsEnsure data independence and reusability
|Maintaining test stability
|Regularly review and update automated scriptsImplement version control for test scripts
|Clearly define regression testing scope for each iterationUse risk-based testing for focus
|Communication and collaboration
|Foster a culture of collaboration and open communicationUse collaboration tools
|Identify and document dependenciesPerform impact analysis and implement testing strategies
|Test environment challenges
|Invest in robust and easily reproducible test environmentsUse virtualization or containerization
|Adapting to change
|Foster an agile mindset within the testing teamEncourage continuous learning and adaptation
|Measuring test coverage
|Implement testing tools to measure and visualize test coverageConduct regular reviews and adjust test cases
By combining these techniques and adapting them to the specific needs of your agile project, you can effectively manage regression testing challenges and ensure the quality of your software throughout its development lifecycle.
Examples of regression testing in Agile
Healthcare application example:
A healthcare application is introducing a new telemedicine feature for remote consultations.
Regression testing focus:
- New feature validation: Test the functionality of scheduling appointments, video/audio quality, and data security in the telemedicine feature.
- Existing patient data: Conduct regression tests on existing functionalities like patient records, prescriptions, and appointment booking to ensure no data loss or corruption due to the new feature.
- Compliance and security: Validate that the new feature adheres to healthcare regulations and maintains patient data confidentiality.
Regression testing guarantees the seamless integration of a new feature while safeguarding critical patient data and upholding compliance standards in the healthcare app.
Financial software example:
A financial software company is updating its accounting software to include support for cryptocurrency transactions.
Regression testing focus:
- New transaction type: Test the addition of cryptocurrency transactions, including calculations, transaction security, and reporting.
- Existing financial functions: Conduct regression tests on core accounting functions like ledger balancing, tax calculations, and financial reporting to ensure accuracy and consistency.
- System integration: Validate that integrating cryptocurrency transactions does not impact existing banking or investment modules.
Regression testing ensures the successful introduction of a new transaction type without compromising the accuracy and integrity of existing financial functionalities in the software.
In these examples, regression testing is crucial in validating new features while safeguarding existing functionalities, user data, and compliance standards across diverse domains.
A test case management tool like TestRail simplifies regression testing by organizing all test cases in one place. It helps track changes, manage results, and plan and execute tests smoothly across different project stages. This streamlined process allows quick identification and resolution of regressions, enhancing software quality and stability.
Image: In TestRail, you can triage risks faster by monitoring the progress of all your regression testing activities in one place.