Hi Pedro,
As per my understanding this is system standard behavior for Direct Procurement and you cannot change this behavior.
Please find my comments according to my understanding of direct procurement:
This almost fits our scenario, but the problem here is if you have 10 Production orders, the MRP will create 10 Purchase requisitions (Account Assignment: F (order)), but we want that the MRP create only 1 Purchase requisition with the total quantity of the materials.
This requirement cannot be fulfilled using direct procurement since direct procurement is treated as a separate segment in MRP.
Also, the MRP will ignore the existing stock of the purchasing materials.
This is again standard, direct procurement materials are generally to be used in the production directly, i.e., they are not kept in stock. MRP will exclude the stock from calculation, and it will calculate segment-wise stock/requirement.
I do not see any possibility of changing these behaviors when using direct procurement.
Best Regards,
Rajen