For reusing model components, it is crucial to understand what information is needed and how it should be presented. The centrality of abstraction being inherent in the modelling process distinguishes model components from software components and makes their reuse even more difficult. Objectives and assumptions which are often difficult to explicitate become an important aspect in describing model components. Following the argumentation line of the Web Service ontology OWL-S, we propose a set of metadata which is structured into profile, process model, and grounding to describe model components. On the basis of the specific model component Tryptophan Synthase, its metadata is refined in XML. The reuse of the described model component is illustrated by integrating it into a model of the Tryptophan operon.
