A requirements document, on the other hand, would state that the software must handle error states reasonably and effectively, and provide explicit feedback to the users. The specifications show how to meet this requirement. Specifications may take several forms. They can be a straightforward listing of functional attributes, they can be diagrams or schematics of functional relationships or flow logic, or they can occupy some middle ground. Specifications can also be in the form of prototypes, mockups, and models.
Project specifications are much more important for determining the quality of the product.
Every rule and functional relationship provides a test point. Adherence to specification is not a perfect measure, however. A mismatch between the program and its specification is an error in the program if and only if the specification exists and is correct. A critical part of the quality assurance role is proactive involvement during the project requirements analysis and specification phases, where the rational and customer-centered point of view of the QA analyst can be applied to the project's rules before any code is written. Catching problems when the requirements and specifications are being hammered out is the ideal time to head off problems.