Today's companies more and more embrace the utilization of inter-organizational services as part of their internal business processes. The benefit from this outsourcing is manifold, ranging from lower maintenance burden to predictable cost. One problem is, that for companies in order to not bind themselves to a single service provider, they have to ensure that the services they consume are interchangeable. Therefore a marketplace for services, based in a common set of rules, that allows companies to stay flexible when selecting business partners is needed. In this thesis we introduce a hybrid...