What do you do if your regression test results are not reliable?

Working in several complex projects we identified that most poor regression test scenarios are related to one or many of below: 1- obsolete Test Case 2- Requirements that keep on changing with poor documentation 3- Design chane across the life cycle of the product 4- Experts leave the company who has the domain knowledge causing business gaps 5- reusing same test data in every regression run 6- poor time management and risk based testing 7- Aggressive timelines and limited time to launch due to poor quality code or deliverables

From the defect leakage, we need to see where the gaps are. We need to find the route cause analysis for the bugs and need to update the test cases accordingly. Regression tests need to be reviewed by BA and Products so that we can get more insights into it.

Identify the root cause using 5W &1H method and eliminate the causes of the defect in order to prevent their re-occurrence. Use Cause & Effect Diagram (Fish-Bone Diagram) to find root cause (Man, Machine, Material,Methodology, Environment). Review the effectiveness of action taken. Deploy the action Horizontally

Begin by thoroughly analyzing the regression test results. Look for patterns, inconsistencies, and unexpected behavior. Investigate whether the issue lies in the test environment, test data, or the test cases themselves. Consider factors such as changes in the application code, dependencies, or external systems. Engage with developers, testers, and stakeholders to gather insights and pinpoint the underlying cause.

Fixing the root cause involves identifying and addressing the underlying issue that is causing a problem or defect. Instead of just addressing the symptoms or immediate effects of a problem, fixing the root cause aims to prevent the issue from recurring. This may require thorough investigation and analysis to understand the underlying factors contributing to the problem. Once the root cause is identified, appropriate corrective actions can be taken to address it and prevent similar issues in the future.

Address Environmental Issues: If the root cause lies in the testing environment, rectify those issues. This could involve fixing database configurations, application settings, or ensuring consistent resource availability during testing. Debug Test Code: If the test code itself is faulty, fix the bugs or errors in the scripts. This might involve improving the logic, handling edge cases more effectively, or using more robust testing frameworks. Update Tests for Changes: Regression tests should evolve alongside the application. If the application has undergone significant changes, update the test scripts to reflect those changes and ensure they accurately test the current functionality.

If my regression test results aren't reliable, I'd start by investigating the root cause, checking test cases, data, and environment stability. Collaboration with the development team is key, and implementing corrective actions based on findings is essential. Afterward, I'd re-run tests, validate results, and establish continuous monitoring for improvement.

1. Investigate the root cause as to why the test results are not reliable. This could be due to issues with the test environment, test data, test scripts, or even the application under test. 2. Improve the test environment by mimicking the production environment. Check for differences in hardware, software, network configurations, and other environmental factors that could impact the test results. 3. Verify the test data used in the regression tests is valid & accurate. Missing or incorrect test data can lead to unreliable results. 4. Review the test scripts to identify any flaws, or inconsistencies that could be affecting the reliability of the results. 5. Maintain revision control of your test scripts.

Once you’ve identified the problem, work collaboratively to address it. If the issue is related to the test environment, ensure that it’s stable, properly configured, and reflects the production environment. If test data is causing inconsistencies, validate and sanitize the data. Ensure it covers relevant scenarios. Review and update test cases affected by the root cause. Modify or create new test cases as needed. If the issue is code-related, collaborate with developers to fix defects or improve code quality.

Improve Test Design: Invest in designing high-quality, well-structured regression tests. This includes using clear and concise steps, proper data setup and teardown, and incorporating error handling mechanisms. Automate Test Maintenance: Consider automating regression test maintenance tasks. This could involve using tools to automatically update tests based on code changes or to identify and fix flaky tests. Continuous Monitoring: Integrate regression testing into your continuous integration/continuous delivery (CI/CD) pipeline. This allows you to catch regressions early and quickly pinpoint the root cause before new code is deployed.

Implement preventive measures to avoid similar issues in the future: Test Data Management: Regularly review and update test data. Maintain a representative dataset. Automated Regression Suites: Enhance and maintain automated regression test suites. Run them frequently. Version Control: Ensure proper version control for test scripts, test data, and application code. Continuous Monitoring: Monitor test execution results continuously. Set up alerts for anomalies. Documentation: Document the root cause analysis and preventive actions taken. Training and Awareness: Educate the team on best practices for reliable regression testing.

To prevent these issues from happening in future, you can - Establish a review process for test cases, involving Product team and Developers to validate steps and assertions for accuracy and completeness. - For Test Data issues, one can implement protocols for managing test data, including regular validation and updating to ensure accuracy and relevance. - Document lessons learned from past incidents and share best practices

Improve test design and review and monitoring all the three steps.TEST review , test monitoring and test feedback that ensure your regression testing is reliable

If the results obtained are not reliable, I would go in to verify the data and the calculation made to initially rule out errors of methodology or inputs, if everything is ok I would go in to advance a complete analysis that leads me to understand these results and their origin.

- Review the test cases to ensure they are comprehensive and free from errors that could lead to inconsistent results. - Ensure the test environment is stable and consistent across runs - If using automated tests, check the scripts for accuracy, reliability, and maintainability to prevent errors. - Evaluate the strategy to ensure it covers all critical areas and is effective in detecting regressions.

Following are some of the important points to consider for improving the reliability of regression test results: - Evaluate test environment stability. - Ensure quality and consistency of test data. - Review test case design and coverage. - Assess effectiveness of test automation strategy. - Integrate regression tests into CI/CD pipeline. - Implement monitoring and alerting mechanisms. - Analyze test reports for patterns and trends. - Invest in team training and skills development. - Foster collaboration and communication. - Establish feedback loops for iterative improvement.

If regression results are not reliable, I would follow mentioned steps. 1. Check the Outliers if any and deal with it. 2. Check the assumptions if any of them are violating 3. Increase sample size 4. Try to include more independent (explanatory) variables Try using ML Algorithm such as Decision Tree Regression, Random Forest Regression etc….

If your regression test results are not reliable, it's crucial to refactor your tests to align with changes in the system under test. Outdated or ineffective tests undermine confidence in the system's quality. Model-based testing tools optimize test coverage by generating new tests based on an up-to-date model of the system's behavior. They allow you to refactor the overall test pack, eliminating tests that are no longer valid due to system changes. This ensures a comprehensive, relevant test suite that provides reliable verification as the system evolves, maximizing test effectiveness and efficiency.

* Monitoring and Alerts: Implement monitoring tools that alert the team when a test fails. This allows for immediate attention to failures rather than waiting until the end of a testing cycle. * Feedback Loops: Establish a feedback loop with the development team to ensure that insights from testing are integrated into the development process effectively. * Risk Analysis: Not all tests are of equal importance. Conduct a risk analysis to prioritize tests based on the criticality of the features they cover. This helps in focusing efforts where they are most needed. * Leveraging Metrics: Use metrics to measure the stability and reliability of your tests over time.