The aggregation relationship indicates that an element groups a number of other concepts. The example below includes the two ways to express the assignment relationship. The example shows two ways to express that the Customer File aggregates an Insurance Policy and Insurance Claim:
- The aggregation relationship has been inspired by the aggregation relationship in UML class diagrams. In contrast to the composition relationship, an object can be part of more than one aggregation.
- An aggregation relationship is always allowed between two instances of the same element type.