Evorm: a Conceptual Modelling Technique for Evolving Application Domains Weide. Evorm: a Conceptual Modelling Tech- Nique for Evolving Application Domains. Tech

In this paper we present EVORM, a modelling technique for evolving application domains. First a delim-itation of the concept of evolution is provided, based on an earlier developed general theory for such evo-lutions. This theory makes a distinction between the underlying information structure and its evolution on the one hand, and the description and semantics of operations on the information structure and its population on the other hand. Main issues within this theory are object typing, type relatedness and iden-tiication of objects. EVORM is the result of applying this general theory to the object role modelling technique PSM, a generalisation of ER, EER, FORM and NIAM.