One thing that’s not intuitive in Visio 2007 is how to change the text on a UML activity diagram signal element. When you first drag the signal shape on to an activity diagram it displays the text “<no send action>”.
No amount of editing properties will change that unless you do some thing like the following:
1. Create a new Static Structure Diagram (if you haven’t got one already).
2. Using the UML Static Structure shape palette drag a new Signal on to the Static Structure Diagram.
3. Right-click on the signal and open Properties.
4. Change the Name to whatever you want to signal to be called.
5. Return to your Activity Diagram and using the UML Activity Diagram palette add a Signal to your activity diagram.
6. Right-click on the signal and open Properties.
7. Choose Actions from the left-hand pane.
8. Select the Send Action and choose Properties.
9. Under Send Action you can now see the signal you added to the Static Structure diagram in the Signal drop down. Select it.
10. OK to all the dialogs and now the name of the signal appears on your signal shape.
Intuitive, isn’t it!