An ontology is a formal, explicit specification of a shared conceptualization of some fragment of domain, which is understandable for both people and intelligent systems. However, it is rather complicated for a domain expert with limited ontology expertise to create complete and consistent ontology, which could answer required competency questions. In this paper we consider the approach with the use of ORM2-diagram as an intermediate model for creating an OWL2-ontology. This approach requires specialized conversion rules allowing to map ORM2-diagram into OWL2-ontology. In this study we revealed that existing conversion rules do not comply with ORM2-semantics. We improved existing conversion rules for Entity Type and Subtyping elements of ORM2 notation. Also we automated the process of mapping ORM2-diagram (consisting of base elements of ORM2 notation - Entity Type, Value Type, Subtyping, Unary Role, Binary Role) into OWL2-ontology as well. As result of this study, we developed a software component, which is part of plugin for ontology editor Protégé. This paper also describes an experiment that confirms the effectiveness of the developed module. It is proven that module allows to exclude mistakes encountered in conversion ORM2-diagram to OWL2-ontology and to reduce conversion time as well.

Keywords: explicit knowledge representation, visual model, intermediate model, ontology modeling, ontology, OWL2, ontological pattern, ORM (Object-Role Modeling), ORM diagram