Arnaud Cuccuru

Metamodels in Europe: Languages, Tools, and Applications

This article provides an overview of current efforts in Europe for using metamodeling in the integrated development of critical systems such as automotive electronics. It distinguishes between lightweight versus heavyweight approaches, surveys a number of related current European projects, and gives details about the Speeds project to illustrate the role of metamodeling-driven system engineering.

Formalizing Execution Semantics of UML Profiles with fUML Models

UML Profiles are not only sets of annotations. They have semantics. Executing a model on which a profile is applied requires semantics of this latter to be considered. The issue is that in practice semantics of profiles are mainly specified in prose. In this form it cannot be processed by tools enabling model execution. Although latest developments advocate for a standard way to formalize semantics of profiles, no such approach could be found in the literature. This paper addresses this issue with a systematic approach based on fUML to formalize the execution semantics of UML profiles. This approach is validated by formalizing the execution semantics of a subset of the MARTE profile. The proposal is compatible with any tool implementing UML and clearly identifies the mapping between stereotypes and semantic definitions.

Generating execution infrastructures for component-oriented specifications with a model driven toolchain: a case study for MARTE's GCM and real-time annotations

The development of embedded Systems becomes more and more complex. Model driven engineering can help to manage this complexity by specifying real-time properties in a declarative way and automating the deployment. The UML profile MARTE is a OMG standard that allows to model real-time properties. However, there is no execution infrastructure that supports MARTEs generic component model (GCM) and the application modeling (HLAM). The contribution of the paper is twofold: it presents a proposition of a component model with flexible interaction support that allows to tailor code generation to domain and target requirements. Second, it will show how MARTEs GCM concepts can be implemented by means of the proposed component model. The proposed component model has been largely developed in the context of the French national project Flex-eWare with the intention to unify major components model, notably the CORBA component model (CCM) and Fractal. The paper explains the major elements of this model in detail and shows how specific connector and containers can implement MARTE specifications. We present the tool support that is integrated into a UML modeler and based on model-to-model and model to text transformations.

Extending the Standard Execution Model of UML for Real-Time Systems

The ongoing OMG standard on the “Semantics of a Foundational Subset for Executable UML Models” identifies a subset of UML (called fUML, for Foundational UML), for which it defines a general-purpose execution model. This execution model therefore captures an executable semantics for fUML, providing an unambiguous basis for various kinds of model-based exploitations (model transformation, code generation, analysis, simulation, debugging etc.). This kind of facility is of great interest for the domain of real time systems, where analysis of system behavior is very sensible. One may therefore wonder if the general-purpose execution model of fUML can be used to reflect execution semantics concerns of real-time systems (e.g., concurrency, synchronization, and scheduling.). It would practically mean that it is possible to leverage on this precise semantic foundation (and all the work that its definition implied) to capture the precise execution semantics of real-time systems. In this paper, we show that this approach is not directly feasible, because of the way concurrency and asynchronous communications are actually handled in the fUML execution model. However, we show that introducing support for these aspects is technically feasible and reasonable in terms of effort and we propose lightweight modifications of the Execution model to illustrate our purpose.

Templatable metamodels for semantic variation points

In the field of Domain Languages Engineering, Semantic Variation Points are an important issue. This crucial information is often related to the dynamic semantics of systems. Identifying and understanding it is a requisite for all model-based activities (design, simulation, test, formal verification, etc.). Most of the time, semantic variation points are only informally identified in a documentation associated with a metamodel: they are not part of the metamodel itself, and there is currently no mechanism to capture them explicitly. We propose a template-based notation enabling semantic variation points to be clearly and explicitly identified within the metamodel, using template parameter definitions. Semantic variation points can then be intuitively fixed by parameter binding at both model and metamodel levels. We illustrate our proposal with a templated version of the UML 2 state machine metamodel. Finally, we describe a prototype implementation of our mechanisms in the context of the Eclipse Modeling Framework.

Towards UML 2 extensions for compact modeling of regular complex topologies

The MARTE RFP (Modeling and Analysis of Real-Time and Embedded systems) was issued by the OMG in February 2005. This request for proposals solicits submissions for a UML profile that adds capabilities for modeling Real Time and Embedded Systems (RTES), and for analyzing schedulability and performance properties of UML specifications. One of the particular request of this RFP concerns the definition of common high-level modeling constructs for factorizing repetitive structures, for software, hardware and allocation modeling of RTES. We propose an answer to this particular requirement, based on the introduction of multi-dimensional multiplicities and mechanisms for the description of regular connection patterns between model elements. This proposition is domain independent. We illustrate the use of these mechanisms in an intensive computation embedded system co-design methodology. We focus on what these factorization mechanisms can bring for each of the aspects of the co-design: application, hardware architecture, and allocation.

Enhancing UML Extensions with Operational Semantics.

The objective of the ongoing OMG standard about a foundational UML subset semantics (fUML) is twofold: providing operational semantics for a UML subset, and ease unambiguous and automatic model exploitations. Its impact could however be limited if usual UML profiling practices do not evolve. Profiles are the traditional way to specialize UML semantics and handle semantic variation points. However, they are usually defined in a way that only informally addresses the semantic issue, potentially limiting the benefits that fUML could bring in UML based methodologies. UML profiling practices must evolve: we propose to explicitly encapsulate operational semantics into stereotype operations, and provide a way to intuitively handle semantic variation points through template parameters. We illustrate the usage of these mechanisms and demonstrate their potential benefits. We also show that no UML metamodel modifications are required to support them, so that their implementation in L3-compliant UML tools is straightforward.

Designing heterogeneous component based systems: evaluation of MARTE standard and enhancement proposal

Building complex real-time embedded systems requires assembly of heterogeneous components, possibly using various computation and communication models. A great challenge is to be able to design such systems using models where these heterogeneity characteristics are described precisely to assist the next step of the development including implementation or analysis. Although the new MARTE standard provides the core concepts to model real-time components using various communication paradigms, we state in this paper that MARTE extensions have still to be made and we propose to extract common features from several component based approaches in order to support finer compositions of heterogeneous sub-systems.

Semantic Framework for Internet of Things-Aware Business Process Development

The proliferation of connected devices, wherein Sensors, Actuators and Tags (such as Radio-Frequency Identification (RFID)) are able to seamlessly communicate to their environment and to each other for sharing information or to perform some actions has created the Internet of Things (IoT) ecosystem. These devices expose their functionality via standard services and application programming interfaces (APIs). They are considered to be one of the key technology enablers to foster the vision of a smart world, comprising of smart objects, smart supply chain management, smart manufacturing (Industry 4.0), smart buildings, to name a few. In fact, today these IoT devices continuously take part in various business processes that are being executing within the boundaries of the same enterprise or in different enterprises. Thus, there is an evident need to model these processes that are associated with IoT resources in a formal and unambiguous manner. However, in context of business processes, these is a lack of formalized and explicit description for IoT resources, thus hampering their efficient modeling and management. To bridge this gap, we propose a semantic framework for developing IoT-aware business processes as follows, (i) formalizing IoT resource description w.r.t Internet of Things Architecture (IoT-A) reference model in context of business processes, (ii) formalizing IoT properties and allocation rules for optimal resource management and (iii) resolving resource conflicts based on strategies. To illustrate the feasibility of our framework, we evaluated our semantic model for coverage of concepts in IoT-A reference model along with development of a proof of concept tool for integrating the IoT resources and our semantic model during the process modeling phase.

Towards a systematic, tool-independent methodology for defining the execution semantics of UML profiles with fUML

The purpose of UML profile mechanism is to design domain specific languages (DSL) based on UML. It exists a wide range of UML profiles: MARTE, ROOM, SysML. Current profile design methodology only considers the syntactic part of the language and keeps informal the execution semantics description. This impairs Model Driven Engineering (MDE) promises which advocates for executable models. This paper presents a systematic approach to formalize the execution semantics of UML profiles using foundational UML (normative specification) which defines a precise semantics for a subset of UML. This approach is integrated into the reference profile design methodology. It is illustrated on a small profile to support Turing machines. It demonstrates capability to execute resulting profiled models through the defined semantics.