Verification and validation are at the heart of all software testing efforts. Together, they check that software fulfills both user expectations and technical requirements.
Although there are many ways to answer this question, the simplest answer is verification and validation. Verification and validation go beyond just test activities or test types. They define not only how to test, but, more importantly, why it's important to test.
Testers ensure that software meets specifications and is fit for purpose. Verification and validation are the activities that enable that; they are the purpose of and basis for all software testing.
Delve into the definitions, techniques and approaches to verification and validation. Review the aspects of each, and learn how they work together in a comprehensive test strategy to more fully understand the purpose of testing.
Verification vs. validation in testing: What's the difference?
It is important to note that verification and validation are both critical test processes and should be included in every comprehensive test strategy. Verification and validation are not an either-or. If someone poses this question, the answer is almost always both. Verification and validation are different processes; they focus on different objectives and use different approaches and techniques.
For quick reference on the differences between the two techniques, see this comparison table.
Verification
Validation
Objective
Determines if the application meets specifications and technical requirements
Determines if the application is fit for purpose and meets user expectations
Focus
Functionality
UX
Resources
Developers and testers
Product owners and users
Occurrence
Throughout the SDLC
After functional testing
Test techniques
Static and dynamic testing
User acceptance and beta testing
Predominant test types
Automated and manual
Manual
What is verification in software testing?
Verification is the process that determines if software meets the specified requirements. This process takes place throughout the SDLC and answers the question: Is the software built correctly? For example, if a software application's login function is supposed to lock a user out after three incorrect attempts, the testing team must verify that the application does this successfully.
Verification and validation go beyond just test activities or test types. They define not only how to test, but, more importantly, why it's important to test.
Static testing is the process of inspecting code without executing it. The purpose of static testing is to find defects as early in the process as possible. Teams carry out static testing via code inspection and walkthroughs. It includes reviews of requirements, technical specifications, test documents and code. It also includes checking of wireframes and prototype models. Developers, architects and testers are the roles responsible for performing static testing early in the development process -- sometimes before code development is completed.
Dynamic testing
Dynamic testing processes examine the code in action and ensure that the code functions according to specifications by testing it under various conditions. As such, dynamic testing techniques always involve execution. White box testing, black box testing and nonfunctional testing all fall under the umbrella of dynamic testing. Both developers and testers are responsible for dynamic testing. It begins with unit and component testing during development and continues through all phases of the SDLC. Traditional dynamic test techniques, including equivalence partitioning, boundary value analysis, negative testing, decision tables and state transition testing.
Advantages of verification in software testing
Although it is possible to test an application without performing verification, there are several advantages to including verification in your test strategy. Techniques such as unscripted exploratory testing can ensure that an application works, but verification ensures that it works according to specifications.
The main advantage of verification is including both static and dynamic testing. Static testing finds defects early in the project and makes code cleaner for when dynamic testing commences. Dynamic testing ensures test coverage and facilitates more accurate estimates and metrics.
Testing according to specifications helps teams choose test techniques, such as negative testing and boundary value analysis, that address the requirements. It also enables more accurate test estimates by relating the number of test cases to specific requirements and helps teams measure test planning and execution progress based on the number of test cases written and executed.
Verification tools in software testing
Both test automation and test management tools can be part of the verification process.
In addition to open source tools, commercial test automation tools, such as Playwright, Selenium, Appium, Tricentis Tosca and Micro Focus Unified Functional Testing, are some of the most common for verification. These tools can create regression suites to implement inside CI pipelines. AI-based no-code automation tools are also popular for verification because they have automatic test case generation features.
Test management tools are also critical components of the verification process, as these can document test execution results and capture test evidence. Some examples are QMetry, PractiTest, TestRail and Jira, which has a host of test management add-ons.
What is validation in software testing?
Validation is the process that determines if software is fit for purpose. During validation, teams examine software from the user perspective and aim to answer the question: Does the software meet the intended purpose for which it was developed? Although validation begins later than verification in the software development process, it is an equally important part of the lifecycle.
Software can pass all verification checks but still fail validation checks. For example, the system might meet all technical requirements but still be complicated to use, therefore not meeting the user's needs effectively and not fulfilling its intended purpose.
Validation techniques in software testing
User acceptance testing (UAT) and beta testing are two of the most frequently used techniques for validation.
User acceptance testing
User interaction is the focus of validation; as such, UAT is a primary validation technique. UAT employs end-to-end user journeys, business workflows and UX test cases. Product owners, business analysts, and customer support or customer success managers are the roles responsible for UAT. Testers also sometimes simulate UAT when they perform exploratory testing.
Sometimes, potential users also participate in UAT. Teams can bring users in for a focus group where they perform the main application workflows. The purpose of the focus group is to assess usability and UX and to observe the initial reactions of users.
Beta testing
Beta testing is another validation technique that involves real users. In beta testing, organizations release the application under test to a production-like environment where users execute business workflows and provide feedback.
Organizations monitor the environment for performance, reliability and network issues, and they use beta testing to evaluate application performance across various browser/platform/device combinations.
Advantages of validation in software testing
The main advantage of each validation technique is that they provide invaluable information about the system from the user's perspective. This information is critical to a successful launch and the ongoing commercial success of the application. To be successful, a software application must not only function effectively and efficiently, but also, it must provide a high-quality customer experience that delights users and incentivizes them to continue to use the software.
Validation tools in software testing
Because validation is all about the user, it is critical that teams execute it the way the user would -- this generally requires manual testing. However, to increase efficiency and effectiveness, teams might also employ test tools that have an exploratory testing component that records user actions. Teams can use the recorded actions to create test scripts or generate logs for test documentation. Some examples of tools with this capability are Testpad, PractiTest and Testiny. Chrome also provides an exploratory testing extension that captures screenshots during a session. Teams can also use test management tools to record test plans and results.
Gerie Owen is QA engineering manager at Roobrik. She is a conference presenter and author on technology and testing topics, as well as a certified Scrum master.
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