As you know in EEC6 SAP supplied the ability for the STO ATP to act like the Sales Order ATP. Now everything works as it should expect one Big issue.
As you know when we use a PO (not an STO) the delivery date in the PO will update the ATP for the sales order using checking rule 02. What I am hoping and wanting is since the STO using "A" ATP then then the STO planned delivery date becomes a "requested delivery date". So then it is possible that SAP will use forward scheduling and find external PO's created in the supplying plant to update the STO ATP result. Now since this become schedule line 2, 3 ..... in the STO then why cannot SAP use these dates to update the sales order in the receiving plant. Rather than just using the 1st scheule line date which is equal the STO item delivery date.
My initial solution is to find the STO delivery dates <= today and using "memasspo" to change the delivery date 7 days after today'd date and then doing V_V2.
Lastly, I would honestly like SAP to use some extra logic that if the commited qty <> 1st schedule line qty then it should use the other schedule line qty too to update the sales order ATP result. This causes issues for my current client because we will have to use the above process or when creating SD DN we will get errors because the DN ATP confirms against stock only.
Anybody had the same issue, I can only assume that your assumption and understanding might be close to mine when you switched on the STO ATP in ECC6? Also my current client has not kept their packages and patches up to date since 2008, so unknown whether an EHP helps this with issue.