The EE Model Theory

The EE model theory or MU theory is a theory of models and modelling in general and of conceptual modelling in particular. The foundations part starts with this definition of model: any subject using a system A to obtain knowledge of a system B is using A as a model of B. It conveys clearly the basic understanding of the notion of model as a role notion. Next, the model triangle is introduced, based on the semiotic triangle from the FI theory. It clarifies how complexes (systems or aggregates) of three major sorts (concrete, conceptual and symbolic) can be used as models of each other. By adding two levels of abstraction: the schema level and the meta schema level, the General Conceptual Modelling Framework (GCMF) emerges. It clarifies the notions of conceptual complex, conceptual schema and meta schema, for any Universe of Discourse or system’s world. The elaborations part comprises the presentation and discussion of the General Ontology Specification Language, a universal language for specifying conceptual complexes, conceptual schemas and meta schemas. The syntax of the language consists of graphical as well as textual symbols and constructs. The discussions part starts with a comparison of the GCMF with two other frameworks. Next, the influence of O-O thinking on conceptual modelling is discussed. It appears that O-O thinking blurs two crucial notions in conceptual modelling: the type-instance and the subtype-supertype relationship.