When the supplier posts a confirmation through the WebUI, a ReplenishmentOrderConfirmation_Out message is generated which carries the confirmation information. When the supplier makes confirmation changes, ReplenishmentOrderNotification_Out message is also generated to carry the PO changes to ECC and modify the ECC PO.
However when the supplier makes no confirmation changes, the RON_Out is still generated and is superfluous.
Solution:
With validation check PO_PUBLISH_CHANGED_ITEMS_RON only PO items which were changed (request quantity, request delivery datetime, requested components) are published via ReplenishmentOrderNotification XML to the customer backend. Make validation check PO_PUBLISH_CHANGED_ITEMS_RON “ACTIVE “ in IMG > Supply Network Collaboration > Basic Settings > Validation > SAP Standard Settings > Display Settings for Standard Validation Profiles
SAP SNC Notepad 