Approaches to the Specification of Object Associations

Many practitioners agree on the key role of object associations during the requirements specification and analysis phases of application development, since they contribute to the definition of the semantics of applications. However, the literature shows that there are multiple semantics for associations, and confusion about how they should be represented. As a matter of fact, various interpretations of the concept of association exist, leading to a multiplicity of representations. The contribution of this paper is an exposition of four practical approaches to the formal specification of associations. It also introduces a conceptual model for associations which is used as a baseline for comparing the four approaches to formal specification of associations. These four approaches are based on different constructs of the specification language Object-Z which can be used for formally describing associations. The way these approaches capture the requirements represented by associations is central to selecting the approach to be used for the application development.