The goods receipt for the materials produced through a manufacturing order can be triggered either by SAP ERP or by SAP EWM.
Both processes can be used in parallel. To avoid duplicate inbound deliveries being generated for a production order, you can set the indicator GR From EWM Only in SAP ERP. This allows only the generation of an Expected Goods Receipts from SAP ERP or SAP EWM, and you can only post the goods receipt in SAP EWM.
Technically, when working with deliveries for the goods receipt, you always post the goods receipt in EWM first; the question is where the initial document, for which the GR is posted, is created.
In embedded EWM you can activate the synchronous goods receipt, which does not use deliveries.

Goods Receipt for Manufacturing Order in ERP
For posting a goods receipt (GR) from production, you can use a separate inventory management posting transaction. You can also trigger the posting at the same time as the goods issue posting of the components with the production order confirmation.

Synchronous Goods Receipt Posting
With the synchronous goods receipt no delivery is required. A goods receipt posting in ERP in parallel also post the goods receipt in EWM and triggers the creation of warehouse tasks (WT) for putaway.

Asynchronous Goods Receipt Posting
When using decentral EWM and posting a goods receipt in the SAP ERP system, inbound delivery has to be created, which is replicated to SAP EWM, and which contains the information about the material and quantity being produced.
This inbound delivery is then processed in SAP EWM. Either the GR is posted as the first step, which is then replicated to SAP ERP, and then the physical putaway is done. Or the putaway warehouse task (WT) is created as the first step and with the confirmation of the WT, the GR is automatically posted and replicated to SAP ERP.
Note

On the ERP side, it is necessary to set up the determination of a delivery type and a vendor. As the delivery is an inbound delivery, a vendor is required for it. The determination of this information is done with settings used in several other SAP ERP scenarios, it is not specific to SAP EWM.
The delivery is then mapped in SAP EWM as any other delivery type transferred from SAP ERP. SAP EWM uses document type Inbound Delivery from Production (IDPD) to differentiate that an SAP EWM inbound delivery from production takes place.

