Amine El Kouhen

On the Semantic Transparency of Visual Notations: Experiments with UML

Graphical notations designed by committees in the context of standardization bodies, like Object Management Group OMG, are widely used in the industry and academia. Naive users of these notations have limited background on visualization, documentation and specification of workflows, data or software systems. Several studies have pointed out the fact that these notations do not convey any particular semantics and their understanding is not perceptually immediate. As reported in these studies, this lack of semantic transparency increases the cognitive load to differentiate between concepts, slows down the learning and comprehension of the language constructs. This paper reports on a set of experiments that confirm the lack of semantic transparency of the Unified Modeling Language UML as designed by OMG and compares this standard to alternative solutions where naive users are involved in the design of the notations to speed-up the learning of these languages to new users.

Design and simulation of distributed IMA architectures using TTEthernet: a model-driven approach

Integrated modular avionics architectures complemented with time-triggered ethernet (TTEthernet) provides a strong platform to support the design and deployment of distributed avionic software systems. The complexity of the design and continuous integration of such systems can be managed using a model-based methodology. In this paper, we present an extension for the AADL modeling language to support modeling TTEthernet-based distributed systems. This extension consists essentially in a metamodel of the TTEthernet standard and the implementation of its corresponding concrete syntax. Furthermore, we leverage model transformations to enable undertaking the verification of the system models expressed using our AADL extension. In particular, we propose to transform the system model to a model suitable for a simulation using the discrete event system specification formalism. We illustrate the proposed approach using an example of a navigation and guidance system and we use this example to show the verification of the contention-freed property of TTEthernet schedule.

MID: A MetaCASE Tool for a Better Reuse of Visual Notations

Modeling tools facilitate the development process from modeling to coding. Such tools can be designed using a Model-Driven approach in metamodeling environments called MetaCASE tools. However, current MetaCASE tools still require, in most cases, manual programming to build full tool support for the modeling language. In this paper, we want to specify, using models, diagram editors with a high graphical expressiveness without any need for manual intervention. The second axis is dedicated to the reuse of this specification in other contexts. The redundancy in a diagram editor specification raises the problem of inconsistency during the evolution or the update of this specification. We propose then MID, a tool based on a set of metamodels supporting the easy specification of modeling editors with reusable components.

Time-Triggered Ethernet Metamodel: Design and Application

The combination of the SAE Time Triggered Ethernet (TTEthernet) standard with the Integrated Modular Avionics (IMA) architectures supports the design, deployment and integration of mixed-critical avionic applications. In order to cope with the complexity of these tasks, we advocate for a model-driven engineering methodology. The key element of such methodology is the modeling language, which enables producing relevant models of the system. In this paper, we present a metamodel, which captures the main features and concepts defined in the SAE TTEthernet standard. We discuss how a combination of the TTEthernet metamodel with an IMA metamodel can be used to extend the AADL modeling language to model avionic applications deployed a TTEthernet-networked IMA platform. Finally, we present a case study to illustrate our approach.