Available at Once (AO) Inventory: AO inventory reflects the quantity of products immediately accessible for order fulfillment based on a future-dated inventory report. This method considers only the quantities available on the current date for each SKU. When a Purchase Orders Expected Arrival Date is passed, received or not, its quantities are added to today's inventory levels. If the date is adjusted to a future point, the inventory for all SKUs on that PO is reduced by the PO's quantity, reflecting projected stock levels until the date arrives and the inventory levels are updated again.