Model Parts, Diagrams, Dictionary Items, and Properties > Properties > Multiplicity (property of association)
  
Multiplicity (property of association)
For automation interface information about the Multiplicity property (Start Multiplicity Text or Start Multiplicity Uml, and End Multiplicity Text or End Multiplicity Uml through the automation interface), see the automation interface topic for an Association in the Related Topics.
This property specifies the multiplicity of one end of an Association.
The multiplicity of an Association end is defined by a list box on the Start Role or End Role tab of an Association's Property Pages.
The multiplicity can be set to:
Zero or one
Zero or more
Only one
One or more
Tbd
User defined
By default, the Multiplicity on the Start Role tab is set to Zero or more, and the Multiplicity on the End Role tab is set to Only one.
This property is set on the Options tab of an Attribute's Property Pages.
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The Multiplicity property of an Association can be set through the Property Pages of the Association's Roles.
Zero or one
This property specifies that the item can be associated with no items or one item. On the Class Diagram this multiplicity is shown as follows:
Zero or more
This property specifies that the item can be associated with any number of items, including no items. On the Class Diagram this multiplicity is shown as follows:
Only one
This property specifies that the item can be associated with one (and only one) item. On the Class Diagram this multiplicity is shown as follows:
One or more
This property specifies that the item can be associated with any number of items, except none. On the Class Diagram this multiplicity is shown as follows:
Tbd
This property specifies that the multiplicity of the item is to be decided. On the Class Diagram this multiplicity is shown as follows:
User defined
This property specifies that the item can be associated with only a specific number of items. On the Class Diagram this multiplicity is shown as follows (in this example, 63):
Note that when you select User Defined, an additional box appear for you to specify a value.
The following section provides information about the items and diagrams for which Multiplicity is a property. For more information about an item or diagram, click it.
Is property of
Association