3016257 - SCHEDULELINEDELIVERYDATE cannot be changed by API API_PURCHASEORDER_PROCESS_SRV

Schedule line information of PO cannot be changed by API below:

API_PURCHASEORDER_PROCESS_SRV/A_PurchaseOrderScheduleLine(PurchasingDocument={'PurchaseOrderNumber'},PurchasingDocumentItem={'Itemnumber'},ScheduleLine={'Linenumber'})

• Sourcing and Procurement
• SAP S/4HANA Cloud Public Edition 2011

Call API  API_PURCHASEORDER_PROCESS_SRV to change Schedule line information of PO.

Error below happens:
"The input of field SCHEDULELINEDELIVERYDATE on A_PurchaseOrderScheduleLineType level cannot be processed."

If material type used in PO is Service Material. Because Service Materials do not have a delivery date. They have a start and end date on the item level.

In this case the delivery date cannot be changed.

This is standard behavior.

Fiori app

S4, HANA , KBA , MM-PUR-PO , Purchase Orders , Problem