Software testing is a process of checking whether the software meets the specified requirements and expectations of the users. Software testing can be divided into two main categories: verification and validation.
Verification and validation are often confused or used interchangeably, but they are not the same thing. In fact, they have different objectives, methods, and outcomes. Understanding the difference between verification and validation can help you plan and execute your software testing more effectively and efficiently.
In this blog post, we will cover the following topics:
What is verification and validation in software testing?
Verification and validation are two complementary processes that aim to ensure the quality and functionality of the software. However, they have different focuses and scopes.
Verification
Verification is the process of checking whether the software conforms to the specified requirements and standards. Verification answers the question: “Are we building the product right?“
Verification is done during the development phase, before the software is released to the users. Verification ensures that the software meets the design specifications, follows the coding standards, and adheres to the best practices.
Verification can be done by various methods, such as:
- Reviews: Checking the documents, code, and design by the developers, peers, or experts.
- Walkthroughs: Going through the documents, code, and design with the stakeholders, such as the clients, users, or managers.
- Inspections: Examining the documents, code, and design for errors, defects, or deviations from the standards.
- Static testing: Analyzing the code without executing it, using tools such as code analyzers, compilers, or debuggers.
Validation
Validation is the process of checking whether the software fulfills the needs and expectations of the users. Validation answers the question: “Are we building the right product?“
Validation is done after the development phase, when the software is ready to be delivered to the users. Validation ensures that the software meets the user requirements, solves the user problems, and satisfies the user expectations.
Validation can be done by various methods, such as:
- Testing: Executing the software under different scenarios, conditions, and inputs, using tools such as test cases, test scripts, or test automation.
- Demonstration: Showing the software to the stakeholders, such as the clients, users, or managers, and getting their feedback.
- Beta testing: Releasing the software to a limited number of users, and collecting their feedback, suggestions, or bug reports.
- User acceptance testing: Releasing the software to the end users, and verifying that they accept and approve the software.
Verification vs Validation
| Verification | Validation |
|---|---|
| Checks if the software is built according to the requirements and standards. | Checks if the software meets the needs and expectations of the users. |
| Are we building the product right? | Are we building the right product? |
| Done during the development phase, before the software is released. | Done after the development phase, when the software is ready to be delivered. |
| Uses methods such as reviews, walkthroughs, inspections, and static testing. | Uses methods such as testing, demonstration, beta testing, and user acceptance testing. |
| Requires the knowledge and access to the source code of the software. | Does not require the knowledge or access to the source code of the software. |
Types of verification and validation?
Verification and validation can be categorized into four types, based on the level of abstraction and detail of the software testing:
- Unit verification and validation: Testing the individual components or modules of the software, such as functions, classes, or methods.
- Integration verification and validation: Testing the interactions and interfaces between the components or modules of the software, such as data flow, communication, or integration.
- System verification and validation: Testing the whole software system as a single entity, such as functionality, performance, or reliability.
- Acceptance verification and validation: Testing the software system in the real-world environment, such as usability, compatibility, or security.
Methods of verification and validation?
Verification and validation can be performed by two methods, based on the involvement and perspective of the software testers:
- White box verification and validation:
Testing the software from the internal or structural point of view, such as logic, code, or design. White-box verification and validation requires the knowledge and access to the source code of the software. - Blackbox verification and validation:
Testing the software from the external or functional point of view, such as input, output, or behavior. Black-box verification and validation does not require the knowledge or access to the source code of the software.
Importance of verification and validation?
Verification and validation are essential for software quality assurance, as they help to:
- Detect and prevent errors, defects, or bugs in the software, and reduce the cost and time of fixing them later.
- Ensure that the software meets the specified requirements and standards, and avoid the risk of non-compliance or rejection.
- Ensure that the software fulfills the needs and expectations of the users, and increase the customer satisfaction and loyalty.
- Ensure that the software delivers the intended value and benefit, and achieve the business goals and objectives.
Conclusion
Verification and validation are two important aspects of software testing that ensure the quality and functionality of the software. Verification checks whether the software conforms to the specified requirements and standards, while validation checks whether the software fulfills the needs and expectations of the users. Verification and validation can be done by various types and methods, depending on the level, scope, and objective of the software testing. Verification and validation are essential for software quality assurance, as they help to detect and prevent errors, defects, or bugs, ensure that the software meets the requirements and standards, ensure that the software fulfills the user needs and expectations, and ensure that the software delivers the value and benefit.