
UML/BPMN Metamodel
ModelTree is the abstraction of each element organizing ModelElements using an OwnerShip association.
The ElementOwnerShip association provides a hierarchy of ModelElements that can be managed by the model explorer or by the teamwork facility.
This metaclass is not part of the UML standard. NameSpace is a typical subclass, which takes advantage of the containment facility provided by ModelTree.

Figure 187 : ModelTree (architecture_autodiagram)