You can transform an object of the Subprocess type into an object of the Call activity type.
Prerequisite
No diagram of the BPMN collaboration diagram (BPMN 2.0) type is assigned to the object of the Subprocess type.
Procedure
The object of the Subprocess type and all its occurrence copies are transformed into objects of the Call activity type. In this case, a connection of the invokes type is not created. This happens only if you model an object of the Call activity type.