We present a first step towards a seamless integration of MSCs into the system development process. In particular, we show how scenario-based system requirements, captured in the early system analysis phase using MSCs, are translated into state-based description techniques like Statecharts. To this end, we sketch a schematic integration of MSCs and Statecharts.

syntax of HMSC A hierarchical graph is a mathematical structure that represents the information contents of an HMSC. The set HGid represents the set of all HMSC names. Obviously, this includes the names of BMSCs. Since we did not provide a formal graphical syntax for HMSC we cannot provide a formal mapping from HMSC to hierarchical graphs. However, the intuition is clear. A node in an HMSC contains a reference to another HMSC via its name. Definition 3.3.1 (Hierarchical graphs) A hierarchical graph is either a BMSC or a tuple #id, Nodes, Starts, Ends, Edges, l#, where . id # HGid is the name of the hierarchical graph; . Nodes, Starts, and Ends are pairwise disjoint sets of HMSC reference nodes, start nodes and end nodes respectively with Starts #= ?; . Edges # (Nodes # Starts) × (Nodes # Ends) is a set of edges. An edge (n, n # ) is denoted by n # n # ; . l : Nodes # HGid is a labeling function which associates to a node a reference to an HMSC by means of a...

Today's corporations often must operate across organizational boundaries. Phenomena such as electronic commerce, extended enterprises, and the Internet stimulate cooperation between organizations. Therefore, it is interesting to consider workflows distributed over a number of organizations. Interorganizational workflow offers companies the opportunity to re-shape business processes beyond the boundaries of their own organizations. Two important questions are addressed in this paper: (1) What are the minimal requirements any interorganizational workflow should satisfy?, and (2) How does one decide whether an interorganizational workflow, modeled in terms of Petri nets, is consistent with an interaction structure specified through a message sequence chart?

Abstract. We consider three natural classes of infinite-state HMSCs:

Message sequence charts (MSCs) are a standardised formalism for the specification of the system's communication behaviour that is widely used by industry. Various extensions to MSCs have recently been standardised by the ITU. This paper treats the extension of MSCs with structural operators that allow the hierarchical composition of MSCs. In particular, we propose a linear-time partial-order semantics for this extension that is based on the notion of partial-order multi-sets (pomsets, for short). We provide a compositional denotational semantics for hierarchical MSCs and show that well-known operations on pomsets correspond to the new composition operators in MSCs. The main benefit of our approach is that the semantics is conceptually rather straightforward, as opposed to the operational semantics for MSCs that is currently in the process of standardisation. Keywords Denotational semantics, partial-order multi-set, hierarchical MSC 1 INTRODUCTION In the telecommunication sector, MSC ...

We present prominent features of AUTOFOCUS, a tool prototype for the formally based development of reactive systems. AUTOFOCUS supports system development offering integrated, comprehensive and mainly graphical description techniques to specify both different views and different levels of abstraction of the system. To avoid illdefined specifications, consistency conditions on these system descriptions can be formulated and checked. Furthermore, we show how consistent and executable specifications of systems or components can be animated using the Java code generation of the AUTOFOCUS simulator. Finally, we demonstrate how AUTOFOCUS can be used to simulate the specified system in its system environment using a graphic animation tool as an example.

We introduce Hybrid Sequence Charts (HySCs) as a visual description technique for communication in hybrid system models. To that end, we adapt a subset of the well-known MSC syntax to the application domain of hybrid systems. The semantics of HySCs is different from standard MSC semantics. Most notably,we use a shared variables communication model and assume the existence of a continuous, global clock. Similar to their classic counterpart HySCs can be advantageously used in the early phases of the software development process. In particular, in the requirements capture phase, they improve the dialog between customers and application experts. They complement existing formalisms like hybrid automata by focusing on the interaction between the system's components. Weoutline the key concepts and the usage of HySCs along an example, the specification of an electronic height control system. Then we define their formal semantics.

Component Based Development is considered to be a promising technology to cure the software crisis. However, until now designing and developing component-based applications turns out to be very hard. Current component based development not only involves a component configuration phase, but also writing a lot of glue-code. Much of the existing glue-code in current systems is written to "hack" components together instead of following a careful design. In this paper we introduce a component composition methodology based on the concept of composition patterns. A composition pattern describes an interaction between a set of roles using an extended sequence chart. It serves as a bridge between the design and the implementation. We further propose a component documentation and a set of algorithms based on finite automata theory to perform an automatic compatibility check and glue-code generation to support this methodology.

We provide an automata-theoretic solution to one of the main open questions about the UML standard, namely how to assign a formal semantics to a set of sequence diagrams without compromising refinement? Our solution relies on a rather obvious idea, but to our knowledge has not been used before in this context: that bad and good sequence diagrams in the UML standard should be regarded as safety and liveness properties, respectively. Proceeding in this manner, we obtain a semantics that essentially complements the set of behaviors associated with the set of sequence diagrams, thereby allowing us to use the standard notion of refinement as language inclusion. We show that refinement in this setting is compositional with respect to sequential composition, alternative composition, parallel composition, and star+ composition. 1.

Handling aspects within models looks promising for managing crosscutting concerns early in the software life-cycle, up from programming to design, analysis and even requirements. At the modeling level, even complex behavioral aspects can easily be described for instance as pairs of sequence diagrams: one for the pointcut specifying the behavior to detect, and the second one for an advice representing the wanted behavior at the join point. While this is fine for informal documentation purposes, or even intuitive enough when a single aspect has to be woven, a more precise semantics of both join point detection and advice weaving is needed for using these modeling artifacts for Model Driven Engineering activities such as code generation or test synthesis. This paper proposes various interpretations for pointcuts that allow multiple behavioral aspects to be statically woven. The idea is to allow join points to match a pointcut even when some extra-messages occur in between. However, with this new way of specifying join points, the composition of the advice with the detected part cannot any longer be just a replacement of the detected part by the advice. We have to consider the events (or the messages) of the join point, but also the events which occur between them, and merge them with the behavior specified within the advice. We thus also propose a formal definition of a new merge operator, and describe its implementation on the Kermeta platform.