This paper presents an approach for the design and development of service-driven applications. These applications rely on the collaboration of multiple services that businesses offer to the external community. To ensure that the collaboration of services takes place effectively, service chart diagrams are proposed as a specification technique. These diagrams leverage the traditional state chart diagrams of UML. Furthermore, in service chart diagrams it is advocated that services do not invoke each other. However, they engage conversations before committing themselves to a composition process of services. Categories and Subject Descriptors H.4.5 [Information Systems]: service-oriented applications. General Terms Modeling, Diagrams. Keywords state, service, diagram, conversation.