How to Boost QA Process with Strategic Test Case Prioritization

The goal of software testing is not to test everything that can be tested, as it’s simply not a realistic goal, especially in Agile and DevOps environments. What QA really is about is intelligent testing that will allow us to test as little as possible, but still provide high-quality software for our users. The key to navigating this complexity is focusing on executing the most crucial and relevant tests for the current release. In this article, we will explore the significance of test case prioritization, its benefits, and the techniques to effectively implement it.

What is Test Case Prioritization?

Test case prioritization in software testing is the process of ordering test cases based on their importance, impact, and urgency so that the most critical tests are executed first. This allows QA teams to focus on the highest priority tests so that the most important and high-risk areas of the software are tested early in the development cycle and before changes are released to production.

Imagine you are testing an e-commerce website and you are releasing an update to the payment processing system. You have 50 tests in your backlog. Understanding the relevance and impact of each test for this cycle allows you to focus on the tests that are critical for the payment processing changes. Prioritizing tests will ensure that any critical issues are found and fixed and that some of the other tests, like the user profile management system, have no impact on this release and can be deferred to the next cycle.

Benefits of Test Case Prioritization

There are several benefits of test case prioritization and executing the most high-impact areas first:

• Early Detection of Severe Defects: By testing the most important, high-impact tests first, critical defects can be found and fixed early in the development cycle, mitigating the chance for escaped defects.

• Reduced Time and Costs: Fixing severe defects as early as possible will be much cheaper to fix rather than later in the development cycle or production.

• Efficient Resource Allocation: Prioritizing test cases allows QA teams to allocate their limited resources more effectively. By concentrating on the most impactful tests, teams can optimize their time and effort, avoiding unnecessary testing.

• Improved Test Coverage: Testing high-risk areas thoroughly means more robust and reliable software. Prioritization helps in achieving better test coverage by focusing on the most critical features.

• Faster Time-to-Market: When you concentrate on essential functionalities and high-risk tests first, it can help to release your software or updates quicker to users with more confidence.

Key Factors to Consider in Test Case Prioritization

In order to effectively prioritize test cases, there are several main factors to consider:

• Business Impact: The first main factor to consider is to give the highest priority to test cases that cover crucial business functions. These functions directly impact the key business success elements such as revenue and customer satisfaction. If those functions don’t work as they should, it will simply harm the business.

• Risk: Risk assessment is an integral part of software testing and can’t be overlooked. After conducting a risk assessment, finding and prioritizing areas of the application that are at higher risk of having critical defects is essential. Also, areas that historically had severe bugs are at high risk and should be prioritized.

• Change Frequency: Specific areas or features within the application that you frequently update should also be given a high priority. Changes that happen more often may introduce defects so need to be tested regularly to maintain stability.

• Complexity & Dependencies: Complex features that have multiple parts or complex logic are more likely to have defects. Test cases that have dependencies on other features should be run first. This helps find integration issues and ensures dependent features work together. For example, in a software suite, the interaction between different modules needs to be tested to prevent compatibility issues.

Techniques for Test Case Prioritization

Depending on their needs, QA teams can use multiple test case prioritization techniques to choose which tests should be executed first.

Risk-Based Prioritization

One of the most common and used techniques is risk-based. This technique involves prioritizing test cases based on the risk of failure and the potential impact of defects. As testers conduct risk assessments, they flag some areas as high-risk areas, which are more likely to contain critical defects and have significant consequences if they slip into production. Other areas that are marked as low-risk might be tested in production, or even might not be tested at all since there are minor bugs that it’s not even worth testing and fixing before we release.

Requirement-Based Prioritization

Test cases are prioritized based on the importance of the requirements they cover and the value they provide to the business. Features that are fundamental to business operations or have a high impact on customer satisfaction are tested first. As high-priority requirements can often be defined by stakeholders, it helps to align the testing process with business objectives.

History-Based Prioritization

By using past data such as defect rates and test execution times, testers can determine how to prioritize test cases. Areas that have historically had the most crucial defects or test cases that have taken the longest to execute are given higher priority. Leveraging this data can allow testers to focus their efforts on areas that are more likely to contain issues.

Version-Based Prioritization

Test cases are prioritized based on the version of the software being tested, which is particularly relevant to regression testing. Test case prioritization in regression testing means that when new updates or changes are made, test cases that cover the modified areas and their dependencies are given higher priority. This aimed to ensure the changes didn’t harm other areas with new defects and that the application remained stable.

Hybrid Prioritization

Hybrid prioritization combines elements from multiple different prioritization techniques to create a more holistic approach. For example, a QA team might prioritize test cases by considering both risk and business value or by using historical data along with version-based priorities. Hybrid prioritization allows teams to choose and adjust their approach according to their project’s needs in order to have a balanced testing strategy.

Leveraging AI for Test Case Prioritization

As AI gets more intelligent, it’s being added to many tools and software. In software testing, AI algorithms and machine learning are already being used in various automation tools and test management platforms to enhance different parts of the testing process, including test case prioritization.

The big benefit of test case prioritization using machine learning is that it can evaluate multiple factors like historical defect data, previous test runs, and usage patterns, and give insights on which test cases to run first. By analyzing this information, AI can predict the areas of the software that are most likely to have defects, and which test cases will cover those areas and should be run, helping testers make the right decisions. Test Value Score

One such AI-powered feature that helps with test case prioritization is PractiTest’s Test Value Score. This feature leverages advanced machine learning algorithms to calculate the impact and importance of each test case to your testing process. As each test gets a score from 0-100 to present its value, QA managers can prioritize, identify tests to improve, and retire low-value tests from the schedule.

Test value score holds multiple advantages:

1. Effective Prioritization: Since test cases with higher scores are more impactful, they should be prioritized, ensuring that critical and high-impact areas of the software are tested early and focusing on tests that matter most.

2. Improvement Identification: Low-score highlights tests that need improvement, or even being retired from the testing process. With Test Value Score managers and QA teams can improve their efficiency and get.

3. Informed Decision-Making: Test Value Score provides valuable insights, assisting testers and managers in making informed decisions about test case execution and testing cycles.

Summary

Test case prioritization is key to having both efficient testing and high-quality software. When testers focus on the most important and high-impact tests, they can verify the most critical defects are found and fixed early in the development cycle, saving valuable resources for the company. Understanding the different types of test case prioritization (risk-based, requirement-based, history-based, etc.) allows teams to choose their approach/s according to the project needs.

AI and machine learning can be a significant power in test case prioritization. By evaluating multiple factors like historical defect data, previous test executions, and usage patterns, AI can provide insights that help predict and prioritize the areas of the software most likely to contain severe defects. As PractiTest’s Test Value Score demonstrates, it can highlight tests that provide high contribution and should be prioritized, as well as low-value tests that should be improved or even eliminated. This can help managers to test intelligently, optimize resource allocation, and accelerate release cycles.