Multiple diagram can be combined.
 Exercise 58: Combine existing subprocesses.
![]()  | 1. Open the Combining Subprocesses Exercise model. | 
![]()  | 2. Select the Subprocess 1 and Subprocess 2 elements. | 
![]()  | 3. Right-click either one of the selected subprocesses. | 
![]()  | 4. Select Combine diagrams > horizontally / vertically. | 

A new child diagram is created, containing contents of all selected subprocesses. Double-click on it to change the properties of the new child diagram and type in a name. Note, that the combined diagram element is not updated automatically, if you make changes to the component subprocess elements, i.e. you need to recombine them. Therefore, if you are creating a combined diagram, create the component subprocess elements with their contents first, and then combine the subprocesses.