Validation and Verification in the V-Model: How to Successfully Ensure Product Development

In product development, especially in safety-critical areas, validation and verification are key processes for actively ensuring the quality of products during development.

The V-model is an established process model in product development that systematically integrates tests into the development process and detects errors at an early stage. It is characterized by the fact that it offers a clear, sequential structure with a “V-shape”. Each development step on the left-hand side of the model is opposed to a test and inspection process on the right-hand side. This ensures that each phase from requirements definition, design and implementation through to final verification and validation is systematically safeguarded.

The terms validation and verification play key roles here, which differ as follows:

• Validation: Ensures that the product meets the actual needs of the customer (“Are we building the right product?”).
• Verification: Ensures that the specifications and requirements have been implemented correctly during development (“Are we building the product right?”).

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Success depends on requirements

However, before the actual development takes place along the V-model and the resulting artifacts are validated and verified accordingly, it is essential to first validate the requirements themselves. Techniques such as requirements inspections are suitable for this, in which the requirements are checked for completeness, clarity, consistency and, above all, correctness.
Without this early validation, it can happen that incorrect or incomplete requirements form the basis for designs and developments. In the worst case scenario, this can lead to it only being discovered in the acceptance tests that the developed solution does not meet the actual customer needs.
Validating the requirements at an early stage therefore ensures that all further steps are based on a solid foundation. Expensive rework and delays can thus be avoided.

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Implement refinements correctly

In the next step, the requirements are refined step by step, i.e. broken down from abstract customer requirements to concrete implementation details. Each refinement must be carried out systematically to ensure that it has been correctly derived from the higher level.
Incorrect derivations can lead to misunderstandings, incorrect implementations and therefore serious errors throughout the entire project. A continuous review of the refinements, for example with reviews and simulations, helps to minimize these risks.

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Tests as an integral part of the V-model

Parallel to step-by-step refinement, test cases are also defined and linked to the artifacts of the various refinement levels. Specific test cases must be defined for each refinement level to ensure that the respective implementation is correct:

• Customer requirements: Acceptance tests check whether the solution fully meets customer needs.
• System and solution designs: Integration tests check whether the individual components interact correctly.
• Implementation modules: Unit tests validate the functionality of individual modules or building blocks.

The focus here is on testing against the requirements to ensure that the developed solution is not only technically correct, but also functionally appropriate. This systematic test structure enables continuous quality control.
Important here: changes to requirements must result in immediate adjustments to the test cases. This is the only way to maintain traceability and ensure that the tests remain meaningful.

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Implement validation and verification effectively

Efficient validation and verification therefore requires a structured approach. Here is a summary of the most important aspects that should be considered in the validation and verification process:

1. Clear definition of requirements: Requirements must be precisely recorded and documented. This lays the foundation for targeted validation and verification.
2. Link between requirements and tests: Each requirement has specific test cases. Traceability between requirements and tests minimizes the risk of misinterpretation.
3. Continuous review of refinements: Each refinement should be checked for correctness to ensure that it has been consistently derived from the higher level.
4. Efficient management of requirement changes: Changes must be fully documented and their impact on existing tests and refinements assessed.

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Validation and verification with ReqSuite® RM

The validation and verification described above show how important a structured and systematic approach is in product development.
However, manual or unstructured approaches quickly reach their limits, especially when it comes to managing complex requirements and linking them to test cases. This is where specialized requirements management tools can help to meet these challenges efficiently.
ReqSuite® RM is a modern, flexible requirements management tool specifically designed to help organizations define, manage and track requirements. With its user-friendly interface and intelligent functions, ReqSuite® RM is also able to effectively implement validation and verification processes within the framework of the V-model.

In particular, ReqSuite® RM achieves this with the following functions:

• Automatic checking of requirements: ReqSuite® RM recognizes ambiguities, contradictions or incomplete requirements as soon as they are entered. This makes validation considerably easier and ensures the quality of the requirements.
• Traceability and linking to test cases: All requirements can be linked directly to the corresponding test cases (e.g. acceptance, integration or unit tests). This enables seamless traceability and ensures that each requirement is covered by at least one test case.
• Impact analysis for changes: When changes are made to requirements, ReqSuite® RM automatically analyzes which downstream artifacts, such as tests or refinements, are affected. This ensures the consistency of the entire development.
• Support for refining requirements: Through structured templates and input aids, ReqSuite® RM ensures that refinements are made systematically and correctly. This ensures consistency between the abstract and concrete levels.
• Seamless integration into the development process: ReqSuite® RM supports teams in embedding validation and verification continuously and efficiently into the development process.

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Conclusion

Validation and verification are essential components of a successful development process, especially in safety-critical areas. The V-model provides a clear structure for systematically checking requirements, making correct refinements and validating these through specific tests. The early validation of requirements is crucial to ensure that the right solutions are developed right from the start. It is equally important to continuously check whether all refinements and tests have been correctly derived from the higher level in order to avoid errors and ensure traceability.
A modern requirements management tool such as ReqSuite® RM ideally supports these processes by systematically recording requirements, automatically checking their quality and enabling a seamless link to test cases. The integrated impact analysis also ensures that no important steps are overlooked when changes are made.
Companies that use ReqSuite® RM benefit from a more efficient, transparent and error-free implementation of their validation and verification processes. With the right methods and tools, you not only create the basis for high-quality products, but also ensure the long-term success of your projects. Use these synergies to take your product development to the next level. Schedule a free consultation today!