Use the following tips and techniques when you design a UML 1.5 Activity Diagram.

1. Create one or more swimlanes. You can place several swimlanes on a single diagram, or create a separate diagram for each.
   Warning: You cannot create nested swimlanes.
2. Create one or more activities. You can place several activities on a single swimlane, or create a separate swimlane for each.
   Warning: You cannot create nested activities.
3. For convenient browsing, first model the main flow. Next, cover branching, concurrent flows, and object flows.
   Tip: Use separate diagrams as needed and then hyperlink them.
4. Create Start, End, Signal Receipt, and Signal Sending elements for your swimlanes. If your activity has several Start points, they can be used simultaneously.
5. Create object nodes. You do not link object nodes to classes on your Class Diagrams. However, you can use hyperlinks for better understanding of your diagrams.
6. Create state nodes for your swimlanes.
   Tip: You can create nested states.
7. Optionally, create a History node.
8. Connect nodes by links.
9. You can optionally create shortcuts to related elements of other diagrams.