In Step 5, “Verify & Validate Requirements,” each requirement must be verified and validated to ensure that they are the correct requirement. This ensures that the requirements meet the overall objective of the system and all stakeholder needs. Verification and Validation should be done continuously throughout the development of requirements at every level and as part of baseline activities and reviewed during the System Requirements Reviews (SRR).
Visit: Verification and Validation for more information.
Difference Between Validate and Verify
- Validate: Confirms that a requirement meets the intent of the stakeholder
- Verify: Confirms that the requirements can meet the intended objective of what it meant for.
To validate means to confirm that the requirements meet the operational and system-level needs of a program. “Does the requirements clearly and correctly communicate the stakeholder expectations and needs?” Validation is a quality control process that determines if operational requirements are meet for the overall system to meet to Initial Capabilities Document (ICD) and Capability Development Document (CDD). The analysis is a testing method primarily used in Validation. Validating Requirements ensures that:
- The set of requirements is correct, complete, and consistent,
- A model can be created that satisfies the requirements, and
- A real-world solution can be built and tested to prove that it satisfies the requirements.
- Meets the Stakeholder intent
Requirements designers should go back to stakeholders again with the requirements document and review it. The requirements should also all be traced in a rational database at this point. Take Stakeholder comments and make changes; hopefully, they’re not any. You may need to revisit Step 2, “Write & Document Requirements,” if there are. Repeat the process until there is complete agreement among all stakeholders. When all requirements are agreed upon, a requirements baseline can be established and managed in Step 6, “Manage Requirements.”
The requirement must be verified to prove that each one satisfies their stated requirement. Verification is a quality control process that determines if a system meets its system-level requirements. Inspection and demonstration is the main testing method used in Verification. It confirms that the requirements contain the necessary elements of well-written requirements that adhere to the rules of the organization’s development guidelines. Basically, “Is the requirement written correctly in accordance with the organization’s standards, guidelines, rules, and checklists?”. Verification can be done by:
- Logical argument
- Modeling & Simulation
- Expert Review
- Test and Evaluation (T&E)
Requirements Development Steps:
- Step 1: Gather & Develop Requirements
- Step 2: Write & Document Requirements
- Step 3: Check Completeness
- Step 4: Analyze, Refine & Decompose Requirements
- Step 5: Verify & Validate Requirements
- Step 6: Manage Requirements
AcqLinks and References:
- Defense Acquisition Guidebook (DAG) – Chapter 4
- Requirements Development Checklist
- DAU Systems Engineering Fundamentals Guide
- Space and Missile Systems Center (SMC) Systems Engineering Primer & Handbook
- NASA Systems Engineering Handbook (large 9M file)
- EIA-632 “Processes for Engineering a System” – 7 Jan 99
- White Paper: Writing a Requirements Document “For Multimedia and Software Projects” by Rachel S. Smith
- White Paper: Requirements Development, Verification, and Validation Famous Failures by Bahill & Henderson