Model Parts, Diagrams, Dictionary Items, and Properties > Properties > Composite aggregation (property)
  
Composite aggregation (property)
For automation interface information about the Composite Aggregation property, see Association (automation interface).
This property specifies that an Aggregation is a Composite Aggregation.
A composite aggregation is a form of aggregation with strong ownership and coincident lifetime as part of the whole. Parts with non-fixed multiplicity may be created after the composite itself, but after being created they live and die with it. Such parts can also be explicitly removed before the death of the composite. Composition may be recursive.
On a Class Diagram, a composite aggregation is indicated through a black diamond:
If you create a Composite Aggregation through the Composite Aggregation toolbar button, the Composite Aggregation check box is selected.
This property is available only when the Association represents an aggregation. Note that an Association represents an aggregation when its multiplicity is set to 'part of' or 'is part of' on the Start Role or End Role tabs of an Association's Property Pages.
This property is set on the Options tab of an Association's Property Pages.
The following section provides information about the items and diagrams for which Composite Aggregation is a property. For more information about an item or diagram, click it.
Is property of
Association