Toward a formal theory of model integration

The aim of this paper is to provide the first steps toward a formal theory of model integration. This is supported at least by three arguments: (a) increasing the productivity of the modeling work; (b) decreasing errors; (c) saving time and money. Of course, any formal theory has to be based on a given framework; in our case, we consider only models which satisfy the core concepts of Structured Modeling. The outline of the paper is as follows. After the motivations are pointed out, some preliminary results are given in section 2. Section 3 defines the levels of integration, while in sections 4 and 5 some examples are presented. Remarks and future extensions conclude the paper.On leave from the University of Siena on a fellowship from CNR, Italy. Permanent address: Department of Quantitative Methods, Piazza S. Francesco 17, I-53100 Siena, Italy (contact author).