Availability check using ROD storage location

[lauinator]

At my client we are using the concept of ROD and AFS storage locations. I'm personally an EWM consultant but currently supporting on the ATP Check task force. Here the point came on the agenda, which storage locations should be put into the MRP area for the stocks to be available for the ATP check in the sales order. The gap we are currently facing is the following:
purchase orders are created with the ROD storage location.
Sales order is confirmed based on purchase order
The availability date in the sales order is delivery date in purchase order + GR processing time in material master
Now the GR is posted e.g. in EWM => stock available on ROD storage location.
If the MRP area only contains the AFS storage location what is happening then to the sales order confirmed date when a new ATP check is triggered? Currently the assumption of the SD consultant is that the confirmed date disappears as the purchase order is "closed" based on the goods receipt, but as the ROD storage location is not part of the MRP area, the sales order has no stock anymore?.
I can't believe that this is standard SAP behavior as then all confirmed dates would change for all sales orders that were initially promised based on the purchase order during the time between goods receipt posting and final putaway. This would be a huge gap in SAP if this is the case. As the ATP check is kind of an old function in SAP I can't believe that this gap exists in SAP.
What is your experience in this constellation? Unfortunately I don't find any documentation where the concept of ROD and AFS storage locations is explained in the context of ATP check in the sales order.

[VivekGhulaxe]

Hi Stefan, Please find the storage location MRP blog posting below for your reference,

Storage Location MRP | SAP Blogs

Help required -for MRP Run at storage location level | SAP Community

[lauinator]

Thanks Vivek!
This document mainly speaks about MRP run, though. Is it also valid for ATP check? It speaks about MD04 and stock disappearing from MD04 when parameter is set to 1 so could be?.
However, as in my case as it is an ROD storage location for goods receipts, I'm not sure what happens during MRP run if this stock is excluded. Might be that SAP creates a new planned order as the stock is not considered anymore and supply levels dropped below demand again? This would be bad.
It also doesn't answer my question regarding behavior of ATP check at the time of GR posting. What happens then to the confirmed date in the sales order if the storage location stock from the ROD storage location is excluded? Doest ATP still take the purchase order delivery date + goods receipt processing time into consideration even though it's GR posted or does the supply level drop and sales order loses its confimation until the stock is finally put away and stock moves to AFS storage location?