A Concurrent Region is an “orthogonal conjunctive” component of a composite state, allowing concurrency to be constructed.

A concurrent region is represented on the diagram by a tile of a composite state, seperated from other regions by a dashed line.

ArgoUML currently only supports a horizontal division of a concurrent composite state in regions.

The description of the details panels of a concurrent region is identical to that of a composite state (see Section 19.4, “Composite State” and so is not duplicated here.