Requirements Verification and Validation (V&V) are essential processes in software development, ensuring that the system being built meets its requirements and fulfills its intended purpose. While they are often mentioned together, they serve distinct purposes:
1. Verification:
Verification answers the question: “Are we building the product right?”
- Goal: To ensure that the product is being built according to the specified requirements, design, and standards.
- Focus: Verifies that the product’s development process (e.g., documents, models, and code) conforms to predefined specifications.
- Techniques: Inspections, reviews, walkthroughs, and testing against specifications.
- Example: Checking if a software module adheres to the system design and that it implements the functions as described in the requirement specification.
2. Validation:
Validation answers the question: “Are we building the right product?”
- Goal: To ensure that the final product fulfills the intended use and satisfies the needs of the customer or stakeholders.
- Focus: Validates the system’s functionality, usability, and overall behavior, ensuring it meets the end-user’s real-world requirements.
- Techniques: User acceptance testing (UAT), prototyping, simulation, and system testing in real environments.
- Example: Ensuring that a software system solves the actual problem it was intended to address, and that users can effectively use it to achieve their goals.
Key Differences:
- Verification is concerned with correctness relative to specifications.
- Validation ensures that the product actually meets the needs and expectations of the users or stakeholders.
Why Both Are Important:
- Verification catches defects early in the development process, ensuring that the product is built correctly according to the plans.
- Validation ensures that the final product is useful, usable, and fit for its intended purpose, preventing expensive redesigns after the product is completed.
Example in Software Development:
- Verification: A team verifies a login feature by ensuring that the system checks if passwords are hashed before storing them, based on the technical specifications.
- Validation: A team validates the login feature by ensuring that end users find it intuitive and secure enough for daily use, and that it works in real-world scenarios.
In short, verification ensures that you build the system right, while validation ensures that you’re building the right system.