Quality assuring specification and design

Specification and design have a decisive influence over the quality of software and software-based systems. Much of the value of products is vested in the specification and in early phases of design. Yet the concepts of specification and design are poorly understood, and the practice of quality assurance of specifications, as products in their own right, has not been established. The authors define the notions of specification and design and propose a model that can be used in the measurement-based quality assurance of both. The model is illustrated in an example relating to a very simple communication system