Cardinality

The Cardinality Values tab of the UML Types dialog enables you to add, modify and delete values in the default cardinality list.

The cardinality values are used to define the multiplicity of source and target elements in relationships. This is the range of instances of the role that can be active in the relationship; for example, one employee can be assigned to tasks; for the target role you define the range of instances (such as tasks) the employee could be assigned to.

The cardinality values are also used to define the multiplicity of a Classifying element; that is, the number of instances of the element that can exist. For example, the Class element Building Walls might have a multiplicity of 2..n, meaning that at least two walls must exist (to support the roof) but there can be many walls if the building design required it.

The values have the following formats:

• *, or 0..* - zero, one or many instances
• 0..n - zero or up to n instances, but no more than n
• n - exactly n instances
• n..* - n, or more than n instances.

To access this dialog, select the Settings | UML menu option. Click on the Cardinality Values tab.

To add a new cardinality value, click on the New button. To modify an existing value, click on it in the Cardinality list.

In the Cardinality field, type the required cardinality value. Click on the Save button.