Associaton Types: Motivation, Specification and Implementation with the XModelerML

Associations represent an essential concept of multi-level models. While it is obvious that allowing for an unrestricted number of classification levels of objects is beneficial, associations are usually defined at one level only. There are, however, reasons to enable the definition of association types. Against the background of the explanation of these reasons, we analyze requirements for the semantics of association meta-types and the functionality of corresponding tools. Subsequently, an extension of the FMMLX metamodel is presented that forms the foundation of the implementation of association meta-types. Despite being focused on the FMMLX and the XModelerML©, it should also serve as an orientation for respective extensions of other multi-level languages and modeling environments. The concept and its implementation are evaluated against the requirement and compared to related work.