—The timely and efficient management of faults that affect the quality of services delivered to customers is an important issue for service providers with respect to their business goals. It includes the diagnosis of service faults which deals with the localization of their root causes within subservices and resources being part of the service realization. In this paper our service-oriented event correlation approach, which uses event correlation techniques to automate the diagnosis on the service layer is detailed. Our algorithm for the hybrid rule-based/case-based correlation methodology that also includes recently proposed active probing techniques is presented as well as its prototypical implementation at the Leibniz Supercomputing Center. This implementation is not limited to a small test environment, but has been carried out for requirements of the environment of this large service provider.