We define a subset krtUML of UML which is rich enough to express all behavioural modelling entities of UML used for real-time applications, covering such aspects as active objects, dynamic object creation and destruction, dynamically changing communication topologies in inter-object communication, asynchronous signal based communication, synchronous communication using operation calls, and shared memory communication through global attributes. We define a formal interleaving semantics for this kernel language by associating with each model M krtUML a symbolic transition system STS(M ). We outline how to compile industrial real-time UML models making use of generalisation hierarchies, weak- and strong aggregation, and hierarchical statemachines into krtUML, and propose modelling guidelines for real-time applications of UML. This work provides the semantical foundation for formal verification of real-time UML models described in the companion paper [11].

Abstract. We present a strategy for automatic formal verification of Live Sequence Chart (LSC) specifications against UML models in the semantics of [7] employing the symmetry-based technique of Query Reduction [18, 34, 44] and the abstraction technique Data-type Reduction [34]. Altogether this allows for automatic formal verification without providing finite bounds on the numbers of objects created during a run of the system. Our presentation is grounded on a specific formal interpretation of LSCs for the UML domain in terms of [7] which is rich enough to in particular express properties about objects which are created only during activation of the LSC. 1

Abstract. An extension of the “Object Constraint Language ” (OCL) for modeling real-time and reactive systems in the “Unified Modeling Language ” (UML) is proposed, called OCL/RT. A general notion of events that may carry time stamps is introduced providing means to describe the detailed dynamic and timing behaviour of UML software models. OCL is enriched by satisfaction operators @η for referring to the value in the history of an expression at the instant when event η occurred, as well as the modalities always and sometime. The approach is illustrated by several examples. Finally, an operational semantics of OCL/RT is given. Keywords. Real-time systems, OCL, UML, events 1

We define a subset krtUML of UML which is rich enough to express such modelling entities of UML, used in real-time applications, as active objects, dynamic object creation and destruction, dynamically changing communication topologies, combinations of synchronous and asynchronous communication, and shared memory usage through object attributes. We define a formal interleaving semantics for this kernel language by associating with each model M krtUML a symbolic transition system STS(M ). We shortly outline how to compile models of industrial systems making use of generalisation hierarchies, weak- and strong aggregation, and hierarchical state-machines into krtUML. The main aim of the paper is to provide an executable semantics for krtUML suitable for the formal verification of temporal model properties with existing model-checking tools.

So far most work on formal semantics for the Unified Modeling Language (UML) has concentrated on single diagrams. To provide a formal...

This paper deals with the design of crosscutting features in general and in the UML in particular. We postulate a couple of issues that we think an aspect-oriented designer is faced with when designing crosscutting features. These issues include the independent specification of the crosscutting details and of where to crosscut, the designation of crosscut or referenced elements, the characterization of the composition strategy, and the abstract representation of crosscutting features in the overall design model. Then, we contemplate ways to obey these issues using the UML. In that contemplation, we concentrate on the design of the details of crosscutting features, i.e., the separate specification of the elements that crosscut a given decomposition and of the join points at which that crosscutting takes place, as well as the distinct designation of elements belonging to the crosscut decomposition that are used (e.g., referenced) by the crosscutting elements.