Abstract
Object-Role Modelling (ORM) is a framework for modelling and querying information at the conceptual level. It comes to support the design of large-scale industrial applications allowing the users to model easily the domain. Derivation rules are additional ORM constructs which capture some relevant information of the domain that cannot be expressed in the standard ORM2 language. In this paper, we identify the first-order fragment of subtype derivation rules (without arithmetic operators and aggregation functions) and we provide a provably correct mapping into OWL. This enables complete automated reasoning with ORM2 conceptual schemas enriched by derivation rules, such as detecting inconsistencies and redundancies and deriving implicit constructs. We illustrate the implementation of our formalisation in ORMiE, a plugin for the NORMA ORM2 extension of Microsoft Visual Studio, which automatically maps ORM2 conceptual schemas with derivation rules into OWL and uses a description logic prover as a background reasoning engine.