Requirements based testing
Definition
Designing tests based on objectives derived from requirements for the software component (for example, tests that exercise specific functions or probe the non-functional constraints such as performance or security).[Source: BCS]
Comment
Requirements based testing can be used to prioritise testing activities. Thus if a tester is unfamiliar with a product, they will plan the initial testing activities on the requirements.The results from requirements-based testing can be used to calculate how much of the system has been tested. It does not tell you the complexity of the requirements that have been tested, but it does show what proportion of the requirements have been tested. This testing is only as good as the requirements that have been written, the quality of which can be improved by documentation testing.
