On a notation for real-time system specification

Specification is one of the most important stages in a system´s life cycle. The notations in use in industry at present are deficient and imprecise as well as clumsy in various respects. Taking two of the best known of these notations as a starting point, the authors have added to them in various ways to achieve a notation which has a number of advantages over its predecessors, including clarity. Discarding the finite automata model for specifying control at higher levels eliminates the sequentiality that such models can impose on the analyst where such sequentiality is not part of the requirement. One of the rules governing the formation of these diagrams requires the specifier to show clearly what agent causes an atomic level process to execute; in many cases this will lead to the discovery of ambiguities and incompleteness in the requirements specification. A final advantage is that an automated CASE tool based on the new notation can be used to study the various aspects of system behaviour