|Basic Idoc type||ORDERS05|
Go to transaction WE20 and select the partner (typically vendor in purchase order) for which you want to activate order change message. Under outbound parameters table control press 'Create outbound parameter'. Input partner role, message type, receiver port, basic type.
On message control tab add line with application EF, message type NEU process code ME11 and tick change message flag and save.
If you are not using standard output type NEU then there is an extra piece of configuration which is required for order change EDI message to trigger. In SPRO under menu Materials Management->Purchasing->Messages->Output control->Message Types->Define message types for Purchase Order-> Fine-Tuned Control: Purchase Order (or open view VV_T161M_EF in SM30) add line with Operation 2.
Order change message is triggered only for fields changed configured in SPRO under menu path Material Management->Purchasing->Message->Field Relevant to Printout of Change (Maintain table T166C in SM30). If no EDI message is generated or you are getting message ‘No IDoc items belonging to purchasing document found’ (message ME 760) then check the changed field is in this config table.
See sap help for Sending PO Change Notices via EDI
Also see Note 456127 - FAQ: Electronic Data Interchange (EDI) in purchasing