Toward Validated Composition in Component-based Adaptive Middleware Annie Ressouche 1 , Jean-Yves Tigli 2 , and Oscar Carrillo 1 1 INRIA Sophia Antipolis 2004, route des Lucioles, BP 93 06902 Sophia Antipolis, Cedex France annie.ressouche@inria.fr, ocrozo@gmail.com 2 I3S Laboratory, Nice Sophia University CNRS, Polytech’Sophia SI 930 route des Colles, BP 145 06903 Sophia Antipolis, Cedex, France tigli@polytech.unice.fr Abstract. Nowadays, adaptive middleware plays an important role in the design of applications in ubiquitous and ambient computing. Cur- rently most of these systems manage the adaptation at the middleware intermediary layer. Dynamic adaptive middleware are then decomposed into two levels : a first one to simplify the development of distributed sys- tems using devices, a second one to perform dynamic adaptations within the first level. In this paper we consider component-based middleware and a corresponding compositional adaptation. Indeed, the composition often involves conflicts between concurrent adaptations. Thus we study how to maintain consistency of the application in spite of changes of crit- ical components and conflicts that may appear when we compose some component assemblies. Relying on formal methods, we provide a well defined representation of component behaviors. In such a setting, model checking techniques are applied to ensure that concurrent access does not violate expected and acceptable behaviors of critical components. Keywords: component-based middleware, adaptive middleware, validation, for- mal methods, synchronous modelling 1 Introduction 1.1 Component-based Adaptive and Reactive Middleware Ubiquitous computing follows an evolution of computer science introduced by Weiser [21] two decades ago. A major consequence is the arrival of applications more and more opened on every day environment relying on objects supposedly communicating and intelligent. Devices managed in ubiquitous computing are nowadays heterogeneous, variable, and interacting with a physical environment. Moreover, applications in this domain must often face some variability during execution time. Moving with a mobile user, such applications have not always