Start testing requirements as soon as you start writing them. You make a requirement testable by adding its fit criterion. This fit criterion measures the requirement, making it possible to determine whether a given solution fits the requirement. If a fit criterion cannot be found for a requirement, then the requirement is either ambiguous or poorly understood. All requirements can be measured, and all should carry a fit criterion. Figure B.1. The Volere Shell is a convenient way of ensuring you have all the components to make a complete requirement. This shell can, and should, be automated. |