62 Model-Driven Engineering of Information Systems
Riebisch proposed to explicitly represent cardinalities in Feature Dia-
gram and thus extends them with UML multiplicities [46]. Group cardi-
nalities are introduced and denote the minimum and maximum number
of features that can be selected from a feature group. There are two other
changes: fi rst a feature is allowed to have multiple parents and second, it is
no longer features that are optional or mandatory, but edges.
Czarnecki and Eisenecker adapted Feature Diagrams ...