This thesis introduces similarity measures to be used by comparing XML workflows and RDF or OWL structures. These structures are accessed and converted into a generic graph representation. Two graphs are compared by a measure to conclude in a single value indicating the similarity of the graphs. Similarity is calculated by two different similarity measures, the graph isomorphism measure and the subgraph isomorphism measure. The graph isomorphism measure detects structurally identical graphs and calculates the similarity upon the nearness of the node labels. Structurally different graphs are...