To Depict a Qualified Association
A qualified association relates two classes and a qualifier. The qualifier is a special attribute that reduces the effective multiplicity of an association. You depict a qualified association as a small box on the end of the association line near the class it qualifies.
The next step shows you how to create a qualified association between the ATM class and the Consortium class.
• Right-click the Aggregation link where it joins the Consortium class and choose Show Qualifier. A qualifier attaches to the Consortium class element as shown in the following figure.