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

To demonstrate that the supplier has met every requirement and through reviewing the requirements for features to be tested and conditions to be covered, anomalies and ambiguities can be clarified before too much development has taken place.

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.