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Mapping of domain model to system models

This attribute was introduced as a result of exploring the "faceted classification" alternative. At first, there was some resistance to considering facets as a domain modeling notation at all. Dave Eichmann posited that facets were most useful as a library retrieval mechanism. In exploring why facets seemed weak for domain modeling, one feature that arose was the fact that there is no explicit representation of artifacts or assets themselves within a faceted scheme. In effect, one annotates artifacts with facet profiles, rather than populating a faceted scheme with links to specific artifacts.

This distinction led us to consider the explicit mapping between a domain model and system models as an attribute of the representation approach. For example, RLF has a semantic construct for individuals or instances which provide an intuitive way of modeling the specifics within the notation.

As justification for treating this as a separate attribute from the "coupling" or "representation separability" attribute above, compare the profiles of facets gif with that of RLF gif. Both are separate representations. People do not design systems via either facet schemas or RLF taxonomies. The two notations thus score similarly with respect to this attribute. Yet the linkage from domain model to system model is much more explicit in RLF than in a faceted scheme, and this is at least partly due to the notation expressiveness itself (though obviously tool support will also play a part here).

Conversely, just because the same notation is used for system vs. domain modeling does not mean the linkage between the two will be very explicit. There must be some means of distinguishing domain notations from system notations, and almost by definition such conventions will lie outside the range of the system notation itself (because this is not a relationship found among elements or components of a system). These two test cases seem to confirm that these two attributes can vary somewhat but not completely independently.



next up previous
Next: Kiviat Diagram Examples Up: Axes of the Previous: Differentiation of commonality



Larry Latour
Sat Oct 7 22:45:23 EDT 1995