in the product view (//rrp3) when we select any particular order , double click on the order and click the edit button, then we are able to change the source of supply.
but for the process order (//rrp2) when we click the edit button we are not able to change the source of supply.
what is the reason behind it ? is it a functioality design or what ??
could anyone please explain me about it ??
A process order by design is an ECC owned transaction data compared to Planned Order which is APO owned. However source of supply (PDS or PPM) can be changed in a Process Order in Created (CRTD) status in APO. Once the Process Order is released in ECC (status REL) you can not change the source in APO. Only in ECC you can re-read the master data and make changes in the Process Order which will accordingly flow back to APO.
This is standard SAP design.
What I understand from your question is, you are viewing product view(/SAPAPO/RRP3) for a product and are able to change source of supply for a perticular order, but if this is planned order or process order it is not clear. Further what transaction is RRP2!!
The Process order for which you are not able to change the SOS is a CRTD or REL? In RRP3 you cannot change SOS for a released process order.