The New Association command, accessed from the diagram Toolbox, allows you to create new associations for the current component.
The command prompts you for either bidirectional or unidirectional associations.
A new UMLAssociation is added to the start of the relation for the target entity and a new Component is created and added to the ends of the relation for the UMLAssociation. Also, the following attributes are set for the UMLAssociation: Type is set to Association, Directionality is set to either bidirectional or unidirectional.