Integration of Specification Techniques

Graphical specification notations have gained much popularity in software engineering, as witnessed by the widespread adoption of UML throughout the software industry. Graphical notations are generally characterised by being intuitive to understand, i.e. new users of these notation require little training to become familiar with them. However, few of the graphical notations have a formally defined meaning, so diagrams expressed in such notations are ambiguous – a highly undesirable property for a specification notation. In contrast, formal specification languages have a formally defined mathematical meaning but are comprehensible only to properly educated software engineers. The implication of this is that specifications developed using formal languages are not immediately understandable to the customers and domain experts, and therefore they are difficult to validate. In this thesis we describe the graphical notations of Live Sequence Charts and Statecharts and propose a method using diagrams in these notations for constraining a formal specification expressed in a subset of the RAISE Specification Language. Furthermore, we propose a development method that combines the traditional approach with that of formal development. We give a small example illustrating the application of this method.