When building a system, we must ensure it works exactly as intended. But how can we be confident about that? This is where requirements verification and validation come into play. Although they may sound similar, each serves a distinct purpose. Verification checks if we built the system right, while validation ensures we built the right system. Understanding their differences helps reduce costly errors, save time, and deliver products that meet real user expectations.
What is Requirements Engineering?
Requirements engineering is all about defining what a system should do. It involves gathering, analyzing, documenting, and managing requirements. The goal is to create a clear and complete set of expectations for the system. Without this step, projects risk failure because teams might build the wrong thing or build it the wrong way.
The Core of Requirements Verification
Verification focuses on form. It checks whether we are building the system correctly according to its defined requirements. For example, we verify whether the design results in a system that can meet its input requirements. We also confirm that the system is built according to its specifications.
Key verification questions include:
- Are the integrated requirement sets and design inputs correctly defined?
- Does the design produce a system that can be verified?
- Is the system of interest (SOI) constructed as specified?
- Are internal relationships, like traceability and dependencies, accurately recorded?
- Are interactions with external entities properly documented?
Verification ensures we design and build the system correctly. For systems created by suppliers, verification becomes part of the acceptance process.
The Purpose of Requirements Validation
Validation, on the other hand, focuses on content and intent. It ensures we are building the right system for its intended purpose. Validation answers whether the requirements truly capture what users and stakeholders need.
Important validation questions include:
- Do the requirements express the correct intent?
- Are the requirements complete, consistent, and feasible?
- Can the system be used as intended in its operating environment?
- Will the system prevent unintended users from causing harm?
Validation helps us confirm that we requested, designed, and built what we actually need. It provides confidence that the system can achieve its goals. Moreover, it addresses the risk that the final system may not meet real-world expectations. Validation also includes critical concepts like certification, qualification, and approval for use.
Final Thoughts
Understanding the difference between requirements verification and validation is crucial for system success. Verification makes sure we are building the system correctly, while validation ensures we are building the correct system. Both processes work together to prevent costly mistakes and deliver a product that meets user expectations. By carefully applying these practices, we can create systems that are not only functional but truly valuable to those who use them.
What’s Next?!
Now that you understand the basics of requirements verification and validation, it’s time to explore how to put this knowledge into action. In my next article, Requirements Validation Checks, I’ll walk you through practical ways to assess the completeness, consistency, and correctness of your requirements. Click to learn how these checks can help you identify issues early and build a system that fully meets its intended goals.
Credits: Photo by Yan Krukau from Pexels
