On metamodel superstructures employing UML generalization features

We employ UML generalization features in order to describe multi-level metamodels and their connections. The basic idea is to represent several metamodel levels in one UML and OCLmodel and to connect the metamodels with (what we call) a superstructure. The advantage of having various levels in one model lies in the uniform handling of all levels and in the availability of OCL for constraining models and navigating between them. We establish the connection between the metamodel levels by typing links that represent the instance-of relationship. These typing links are derived from associations that are defined on an abstraction of the metamodel classes and that are restricted by redefines and union constraints in order to achieve level-conformant typing. The abstraction of the metamodel classes together with the connecting associations and generalizations constitutes the superstructure.