R12 12.0.4 Onhand Quantity SQL required

Question

Hi guys
We are a huge retailing company and currently in the process of implementing a custom made application for POS. One of our requirements is to reserve a given quantity against a particular item and once the PO received from the customer, raise a Credit invoice against customer account. Throughout last couple of years after the R12 implementation we kept on adding in-house built modules, mostly for tracking the on-hand quantities. We never used the material reservation until the custom application integration.
As we are planning to go live with the custom built application, we are in a requirement to alter our on-hand quantity scripts throughout the custom modules and reports. Right now we are using the following query to fetch the on-hand quantities:
Select onhand_quantity from
Select sum(onhand_qty) onhand_quantity, inventory_item_id, organization_id, subinventory_code from
Select sum(transaction_quantity) onhand_qty,inventory_item_id, organization_id, subinventory_code from mtl_onhand_quantities
group by organization_id, subinventory_code, inventory_item_id
union all
Select sum(reservation_quantity)*-1 onhand_qty,inventory_item_id, organization_id, subinventory_code from mtl_reservations
group by organization_id, subinventory_code, inventory_item_id
group by inventory_item_id, organization_id, subinventory_code
where inventory_item_id = :item_id and
organization_id = :org_id and
subinventory_code = :subinv_code
Should we consider anything else? We tried to use "apps.INV_QUANTITY_TREE_PUB.QUERY_QUANTITIES" API, unfortunately while compiling we got compilation errors. Please forward your suggestions
regards,

Answer 1

Thanks Sandeep
Unfortunately, we do use move orders quite frequent (OM team just confirmed) and there are just few entries in MTL_MATERIAL_TRANSACTION_TEMP table. A total of 6 records dating back to 2010.
Anyway we are going ahead with the current setup and will include this table if differences are found at later stages. Thank you very much for your replies.
Regards,