In Oracle Order e-Business Suite, we are few very useful UI available.
When ever we create Sales Order It Create Demand and and when ever PO created in System , it create supply.
above query take sales order as parameter and display the Supply and demand for a sales Order ( Good in case of B2B and Drop ship order).
Please note that above will not work as generic query.
This UI will display us the DEMAND(SO) as well as SUPPLY (PO) .We can narrow down further based on SubInventory as well as various Source of Demand as well as Supply.
I will post the screen short of UI soon.