Abstract. Nowadays, object-oriented meta-languages such as MOF (MetaObject Facility) are increasingly used to specify domain-specific languages in the model-driven engineering community. However, these meta-languages focus on structural specifications and have no built-in support for specifications of operational semantics. In this paper we explore the idea of using aspectoriented modeling to add precise action specifications with static type checking and genericity at the meta level, and examine related issues and possible solutions. We believe that such a combination would bring significant benefits to the community, such as the specification, simulation and testing of operational semantics of metamodels. We present requirements for such statically-typed meta-languages and rationales for the aforementioned benefits.

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Use cases are believed to be a good basis for system testing. Yet, to automate the test generation process, there is a large gap to bridge between high-level use cases and concrete test cases. We propose a new approach for automating the generation of system test scenarios in the context of object-oriented embedded software, taking into account traceability problems between highlevel views and concrete test case execution. Starting from a formalization of the requirements based on use cases extended with contracts, we automatically build a transition system from which we synthesize test cases. Our objective is to cover the system in terms of statement coverage with those generated tests: An empirical evaluation of our approach is given based on this objective and several case studies. We briefly discuss the experimental deployment of our approach in the field at Thalè s Airborne Systems.

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Since software systems need to be continuously available under varying conditions, their ability to evolve at runtime is increasingly seen as one key issue. Modern programming frameworks already provide support for dynamic adaptations. However the high-variability of features in Dynamic Adaptive Systems (DAS) introduces an explosion of possible runtime system configurations (often called modes) and mode transitions. Designing these configurations and their transitions is tedious and error-prone, making the system feature evolution difficult. While Aspect-Oriented Modeling (AOM) was introduced to improve the modularity of software, this paper presents how an AOM approach can be used to tame the combinatorial explosion of DAS modes. Using AOM techniques, we derive a wide range of modes by weaving aspects into an explicit model reflecting the runtime system. We use these generated modes to automatically adapt the system. We validate our approach on an adaptive middleware for homeautomation currently deployed in Rennes metropolis.

Where object-oriented languages deal with objects as described by classes, model-driven development uses models, as graphs of interconnected objects, described by metamodels. A number of new languages have been and continue to be developed for this modelbased paradigm, both for model transformation and for general programming using models. Many of these use single-object approaches to typing, derived from solutions found in object-oriented systems, while others use metamodels as model types, but without a clear notion of polymorphism. Both of these approaches lead to brittle and overly restrictive reuse characteristics. In this paper we propose a simple extension to object-oriented typing to better cater for a model-oriented context, including a simple strategy for typing models as a collection of interconnected objects. We suggest extensions to existing type system formalisms to support these concepts and their manipulation. Using a simple example we show how this extended approach permits more flexible reuse, while preserving type safety.

Abstract. Software developers spend most of their time modifying and maintaining existing products. This is because systems, and consequently their design, are in perpetual evolution before they die. Nevertheless, dealing with this evolution is a complex task. Before evolving a system, structural modifications are often required. The goal of this kind of modification is to make certain elements more extensible, permitting the addition of new features. However, designers are seldom able to evaluate the impact, on the whole model, of a single modification. That is, they cannot precisely verify if a change modifies the behavior of the modeled system. A possible solution for this problem is to provide designers with a set of basic transformations, which can ensure behavior preservation. These transformations, also known as refactorings, can then be used, step by step, to improve the design of the system. In this paper we present a set of refactorings and explain how they can be designed so as to preserve the behavior of a UML model. Some of these refactorings are illustrated with examples.