You can dock the following symbols to the boundary of an Activity Partition: Activity Final Node, Central Buffer, Data Store, Decision Node, Flow Final Node, Fork Node, Initial Node, Join Node and Merge Node.
To dock a symbol to an activity partition boundary:
1. Ensure the symbol you want to dock is within the Activity Partition.
2. Right-click the symbol you want to dock, and then click View Options.
3. From the Docking Type list, select On Boundary.
4. Click OK.
5. If necessary, drag the docked symbol to the required position.
Alternatively,
• Drag the symbol to the boundary of the Activity Partition (drop the item when the mouse pointer is over the Activity Partition boundary).