Associations

An Association shows a relationship between two Classes.

Note: Note that Composition and Aggregation are also types of Association.

The type of connection specifically referred to in the Business Object Modeler palette as an Association is not supported in BPM.

The relationship indicates that the Classes need to share data and how one Class can access another. For example, an Association between a Customer Class and an Order Class shows that a Customer has one or more orders. If you have an order, you can locate the customer who placed that order.

Tip: You can create Associations between two classes in the same package, or between classes in different packages.

Associations between Classes affect the Attributes of those Classes. If there is a bi-directional Association between two Classes then each of those Classes will acquire the other Class as an Attribute.

An example of a bi-directional Association is shown below:

In this example, the Customer Class acquires an attribute called Order and the Order Class acquires an Attribute called Customer. In other words, from an Order you can find out about a Customer and from a Customer you can find out about an Order.

An Association can also be from one Class to another.

In a one way Association, only the source Class acquires the attribute of the target Class. In the example, the Order Class inherits the Customer Class as an Attribute but the Customer Class does not inherit the Order Class as an Attribute. In other words, from an order you can find out about a customer but you cannot find out about an order from a Customer.