The idea of service orientation envisions dynamic detection and execution of suitable Web services for solving a particular request. Most realization approaches pay only little attention to the client side of such architectures. We therefore promote a goal-driven approach: a client merely specifies the objective to be achieved in terms of a goal, and the system resolves this by automated detection, composition, and execution of Web services. Extending the WSMO framework, we present a model for describing goals as formalized client objectives that carry all information relevant for automated detection and execution of Web services.