is there any one who has document about the transformation from mega process to mega process BPMN.
Hello, I am not aware of any specific documentation on converting MEGA Process to BPMN.
MEGA Consulting has done this for clients in the past and it is almost easier to just re-create the diagrams manually.
That can be a large task depending on the number of diagrams involved and how well they conform to the standard methodology.
But it does mean that it gets done correctly.