Models describing business processes in a company nowadays have the drawback that they are not machine-processable for two reasons: First the terminology is not formalized. Second the dynamic semantics of the process model is not formally defined. Thus, many discussions and human work is necessary in order to create and maintain process models. However, with a semantic annotation of process models and the usage of ontologies, tasks can be automized and the workload of the user can be reduced to a minimum. In this paper we discuss different possibilities and the added value of annotating a business process model with semantic information.