Metadata modeling

Metadata modeling is a type of metamodeling used in software engineering and systems engineering for the analysis and construction of models applicable to and useful for some predefined class of problems.

Meta-modeling is the analysis, construction and development of the frames, rules, constraints, models and theories applicable and useful for the modeling in a predefined class of problems.

The meta-data side of the diagram consists of a concept diagram. This is basically an adjusted class diagram as described in Booch, Rumbaugh and Jacobson (1999). Important notions are concept, generalization, association, multiplicity and aggregation.

First of all, a concept is a simple version of a Unified Modeling Language (UML) class. The class definition is adopted to define a concept, namely: a set of objects that share the same attributes, operations, relations, and semantics.

The following concept types are specified:

In Figure 1 the three concept types that are used in the modeling technique are illustrated. Concepts are always capitalized, not only in the diagram, but also when referring to them outside the diagram.

In Figure 2 all three concept types are exemplified. Part of the process-data diagram of the requirements workflow in the Unified Process is illustrated. The USE CASE MODEL is an open concept and consists of one or more ACTORS and one or more USE CASES. ACTOR is a standard concept, it contains no further sub-concepts. USE CASE, however, is a closed concept. A USE CASE consists of a description, a flow of events, conditions, special requirements, etc. Because in this case it is unnecessary to reveal that information, the USE CASE is illustrated with a closed concept.

Generalization is a way to express a relationship between a general concept and a more specific concept. Also, if necessary, one can indicate whether the groups of concepts that are identified are overlapping or disjoint, complete or incomplete. Generalization is visualized by a solid arrow with an open arrowhead, pointing to the parent, as is illustrated in Figure 3.

In Figure 4 generalization is exemplified by showing the relationships between the different concepts described in the preceding paragraph. STANDARD CONCEPT and COMPLEX CONCEPT are both a specific kind of CONCEPT. Subsequently, a COMPLEX CONCEPT can be specified into an OPEN CONCEPT and a CLOSED CONCEPT.

An association is a structural relationship that specifies how concepts are connected to another. It can connect two concepts (binary association) or more than two concepts (n-ary association). An association is represented with an undirected solid line. To give a meaning to the association, a name and name direction can be provided. The name is in the form of an active verb and the name direction is represented by a triangle that points in the direction one needs to read. Association with a name and name direction is illustrated in Figure 5.

...
Wikipedia