Software engineering approaches based on a single underlying model (SUM) were developed in response to the need to maintain consistency and coherence between different models and descriptions of software systems in model-driven approaches. Traditional approaches to system specification involve the creation of multiple artifacts and models that must be manually synchronized with each other, and often contain overlapping information. In contrast to those approaches, SUM approaches involve a specification of all information about a system in a single model, from which views of this information can be created.

This paper provides a window into a body of innovative research being pursued by the authors. The SUM environment described brings together elements of orthographic software modeling (OSM) and orthogonal classification architecture (OCA), both of which draw on the idea of orthogonal views in 3D computer-aided design (CAD) environments. By providing a means to specify a multi-level model in which ontological and linguistic elements are specified separately in orthogonal dimensions, the proposed SUM model facilitates change and maintains uniformity. In addition to the model itself, the authors propose tools that allow the specification of multi-level views, or representations of data, so that the model does not contain any information about the layout of a view, only information that affects the meaning of a view.

Finally, the proposed environment provides multi-level aware transformations to keep the views synchronized with the model. While the paper includes some methodological information, the SUM environment is process-agnostic, that is, it could be used to support different system visualization approaches such as the reference model of open distributed processing (RM-ODP) or modeling with the unified modeling language (UML).

This paper should prove valuable to practicing architects and software engineers, as well as anyone with an interest in model-driven approaches to these disciplines.