Multiple Assigner

A multiple assigner will relate any instance within a subset on one side of an Association to any Instance in a corresponding subset on the other side. A partitioning Class, other than the one on each side of the Association, but belonging to the same constrained Loop, partitions the subsets with its instances. Thus each instance of the partitioning Class will be related to a subset of instances on either side of the Association through a constrained Loop. Multiple instances of the Assigner (assigner tokens) will each manage competition within a single subset.

See [MB] and [OOA96] for a complete description and an example of a Multiple Assigner.

Briefly though, consider the Single Assigner example of Clerks and Customers. Now add a third partitioning Class: Department. Each Department instance will then establish a subset of Clerks and Customers that may be related. A separate instance of the Multiple Assigner will manage the creation of references within each Department.