Abstract : Among all programming paradigms, component-based engineering stands as one of the most followed approaches for real world software devel- opment. Its emphasis on clean separation of concerns and reusability makes it appealing for both industrial and research purposes. The Grid Component Model (GCM) endorses this approach in the con- text of distributed systems by providing all the means to define, compose and dynamically reconfigure component-based applications. While structural re- configuration is one of the key features of GCM applications, this ability to evolve at runtime poses several challenges w.r.t reliability. In this paper we present Mefresa, a framework for reasoning on the struc- ture of GCM applications. This contribution comes in the form of a formal specification mechanized in the Coq Proof Assistant. Our aim is to demon- strate the benefits of interactive theorem proving for the reasoning on software architectures. We provide a configuration and reconfiguration language for the safe instantiation of distributed systems.