Section: New Results

CCSL for Models Behavioral Composition

Participants : Julien Deantoni, Frédéric Mallet, Hui Zhao.

The growing use of models for separating concerns in complex systems has lead to a proliferation of model composition operators. These composition operators have traditionally been defined from scratch following various approaches differing in formality, level of detail, chosen paradigm, and styles. Due to the lack of proper foundations for defining model composition (concepts, abstractions, or frameworks), it is difficult to compare or reuse composition operators. In [17], we proposed research directions towards a unifying framework that reduces all structural composition operators to structural merging, and all composition operators acting on discrete behaviors to event scheduling. Our belief is that CCSL, embedding both synchronous and asynchronous relations, is a good candidate to specify the event scheduling corresponding to the coordination of the different behaviors. However, as already stated in previous sections, to achieve such a status, some extensions to CCSL must be proposed. One of them was the possibility to prioritize events in the presence of synchronous relations. This was formally defined in [26] and implemented in the TimeSquare tool.Other interesting extensions are under study in the context of heterogeneous models, see Section 7.13.

As part of Zhao Hui's PhD work, we have proposed a language to bring together subsets of existing predefined languages in a bid to combine their expressiveness. Rather than trying to build the ultimate unified language, sum of all languages, we would rather select meaningful features in existing languages and build a new language based on those features. As an example of application, we have shown how to combine the functional models of Capella with the security models of SysML-sec in an ad-hoc security-aware language for functional analysis [36].