Abstract. Object-oriented methodologies are increasingly used in software development. Despite the proposal of several formally based models, current object-oriented practice is still dominated by informal methodologies, like Booch, OMT, and UML. Unfortunately, the lack of dynamic semantics of such methodologies limits the possibility of early analysis of specifications. This paper indicates the feasibility of ascribing formal semantics to UML by defining translation rules that automatically map UML specifications to high-level Petri nets. This paper illustrates the method through the hurried philosophers problem, that is first specified by using (a subset of) UML, and then mapped onto high-level Petri nets. The paper indicates how UML specifications can be verified by discussing properties of the hurried philosophers problem that can be verified on the derived highlevel Petri net. 1

The emerging Unified Modelling Language has been touted as merging the best features of existing modelling languages, and has been adopted by leading companies and vendors as a universal software modelling language. Some researchers are also looking to UML as a basis for formal methods development. A less known approach is BON (the Business Object Notation), which is based on the principles of seamlessness, reversibility and design by contract, making it an ideal basis for industrial-strength formal methods development of object-oriented software. In this paper, we argue that BON is much more suited for the application of formal methods than UML. We describe the properties that an industrial-strength formal method must have, show how algorithm refinement can be done in BON (as an example of using BON for formal development), and contrast BON with other approaches, including UML, Z, B and VDM.

We address the issue of when software development methods are complementary, i.e., determining when a method is capable of a task that another method cannot perform. Our intent is to examine complementarity in order to help determine when to carry out method integration. We propose some factors for method complementarity, and suggest that contextdependent criteria, such as real-world domain and non-functional development requirements, may have a significant impact on method complementarity.

The main aim of this report is to discuss how the functional and the object-oriented views can be inter-played in order to model the various modeling perspectives of an embedded system. We discuss if the object-oriented modeling paradigm, most likely the predominant one to develop nowadays software, in the broader sense of the term, is also adequate for modeling embedded software and how it must be conjugated with the functional paradigm. More specifically, we present how Data Flow Diagrams (DFDs), the main diagram in the traditional structured methods, can be integrated in an object-oriented development strategy based on the Unified Modeling Language (UML).

A graphical notation for representing Timed CSP (TCSP) specifications is presented. The notation, which integrates features from a number of existing specification languages, including Statecharts, is aimed at providing the means for more easily constructing and managing large TCSP specifications, with the intention of forming the basis for tools and a methodology for applying TCSP in the large. The graphical notation extends TCSP by allowing specifications to be both processes and arbitrary predicates, thus increasing the expressiveness and applicability of the notation. An extendible tool framework, designed for the graphical notation and to be integrated with other tools, is presented. We discuss the features of this framework, especially how it aims to support reasoning about TCSP specifications.

The paper proposes an approach for defining extensible and flexible formal interpreters for diagram notations with significant dynamic semantics. More precisely, it addresses semi-formal diagram notations that have precisely-defined syntax, but informally-defined (dynamic) semantics. These notations are often flexible to fit the different needs and expectations of users. Flexibility comes from the incompleteness or informality of the original definition and results in different interpretations. The approach defines interpreters by means of a mapping onto a semantic domain. Two sets of rules define the correspondences between the elements of the diagram notation and those of the semantic domain, and between events and states of the semantic domain and visual annotations on the elements of the diagram notation. Flexibility also leads to notation families, i.e., sets of notations that share core concepts, but present slightly different interpretations. Existing approaches usually interpret these notations in isolation; the approach presented in this paper allows the interpretation of a family as a whole. The feasibility of the approach is demonstrated through a prototype generator that allows users to implement special-purpose interpreters by defining relatively small sets of rules.