Real Models are Really on M0 - Or How to Make Programmers Use Modeling

This paper discusses the term ’model’ and the role of the level M0 in the four-layer metamodeling architecture of MOF/OMG. It illustrates the failures of the OMG MOF standard and how a model is an abstraction, not a description. We apply two simple approaches: (1) observing the use of models (of real or planned systems) in system development, including prototyping, simulations, and models in general, and (2) comparing modeling with programming. These approaches lead to the conclusion that models should be placed on M0, while UML models are model descriptions. This conclusion leads to a better understanding of InstanceSpecification for description of snapshots, and of metamodeling applied to ontologies