Grouping behaviors in activity diagrams

Creating partitions in activity diagrams
In activity diagrams, you can use partitions to group activity nodes and edges. An activity node can be referenced by one or several partitions.

Specifying partition types in activity diagrams
When you create a partition in an activity diagram, you can specify the type of element that the partition represents.

Changing partition alignment in activity diagrams
In activity diagrams, you can align the partitions and subpartitions vertically or horizontally, or disable the alignment and use them as freeform shapes. By default, the partitions and subpartitions are aligned vertically.

Adding expansion regions and expansion nodes to activity diagrams
An expansion region is a structured activity that can run multiple iterations. An expansion node is a type of object node that represents the flow into or out of an expansion region. An expansion node can contain a collection of inputs and outputs of the same type.