What is the Difference between Available to Reserve & Available to Transact

Available to Transact = Quantity already reserved and ready to transact

Available to Reserve = (Total Quantity in Reservable Subinventory) – (Total Quantity of the Item in the MTL_RESERVATIONS table)

or

(Quantity in your onhand) – (Quantity already reserved for other orders)

How to Calculate the quantity

SELECT SUM(transaction_quantity) INTO TR_QTY
FROM
MTL_ONHAND_QUANTITIES_DETAIL
WHERE
inventory_item_id = :INVENTORY_ITEM_ID
AND organization_id =:P_ORG_ID ;
--
--
SELECT SUM(RESERVATION_QUANTITY)INTO TR_QTY_B
FROM MTL_RESERVATIONS
WHERE inventory_item_id = :INVENTORY_ITEM_ID
AND organization_id = :P_ORG_ID ;
--
--
SELECT SUM(transaction_quantity) INTO TR_QTY_C
FROM
MTL_ONHAND_QUANTITIES_DETAIL
WHERE inventory_item_id = :INVENTORY_ITEM_ID
AND organization_id = :P_ORG_ID
AND subinventory_code IN (SELECT SECONDARY_INVENTORY_NAME
FROM
MTL_SECONDARY_INVENTORIES
WHERE organization_id =:P_ORG_ID
AND reservable_type =2');

Available_to_transact = nvl(TR_QTY,0) – nvl(TR_QTY_B,0);
Available_to_reserve = nvl(TR_QTY,0) – (nvl(TR_QTY_B,0)+ nvl(TR_QTY_C,0));

To find Available_to_transact and Available_to_reserve using API approach, follow this article: – API approach to find On Hand Quantity of an Item