In this paper, the authors propose to realize a comparative analysis of two methods using as tools for modelling, the OWL editor and the Visual Paradigm for UML tool. In the past years, the business environment has adopted ontologies as a mean to process and reuse the domain knowledge. Ontologies provide the premises of resources conceptual modelling. At the same time, companies use, more and more, the Unified Modeling Language (UML) due to the quick and accurate design of the systems where they are concurrent processes. UML and OWL have different objectives and approaches, but they are similar regarding structure representation, respectively class diagram.