Main concepts to handle in ambient computing applications are hard to integrate at the same time. After studying mid- dlewares handling a part of the challenge, and after studying possiblities of main paradigms in name of CBSE and SOA, we present our Service Lightweight Component Architec- ture (SLCA) model, based on three main paradigms: Web services, enabling entities interoperability, dynamic discov- ery, and distribution; lightweight component assemblies to create composite Web services, allowing a high dynamic- ity; and finally events, giving applications reactivity and a maximal decoupling between entities, thus enabling an even higher dynamicity. This leads to conciliate both service ori- ented and event driven approaches in a new way to manage a graph of cooperating services in ubiquitous systems.