Administration and deployment of software systems become increasingly complex. This complexity results from the need of uniform access to applications from heterogeneous terminals through different communication infrastructures. Moreover, applications consists in complex architectures of lot of small components connected together. A first step to simplify deployment is to have an unified and abstract model for representing deployment dependencies and managing them properly. Therefore, we propose here a deployment model and a conceptual foundation for component installation. Installation dependencies and installation rules are expressed in a logic language.