A - O/S or OS means "Out of Stock," as opposed to B/O or BO, which means Back Order. Generally speaking, where there's insufficient inventory to ship, Elliott will back order the balance quantity unless it is set up otherwise.

When a customer orders something from you and you do not have sufficient quantity to ship, you may choose to either "back order" or "not to back order," which is equivalent to "out of stock." When you back order a customer's order, it means you will ship it in the future when you have the inventory. When you mark a customer's order as "out of stock," it means you will not attempt to ship it in the future.

When you don't have sufficient quantity to ship, the system will either back order or mark the balance quantity as "out of stock" at the following levels:

1. Does the customer allow back orders? See the customer file field "43. Backorder OK?" flag. The default value is "Y." Different customers may have different policies.
2. Does the item allow back orders? See the item file field "17. Backorderable?" flag. The default value is "Y." If the item we sell will not be replenished once it is sold, then this flag will be set to "N."
3. The flags in the customer and item files will determine the default value of the "back-orderable" flag in the order line item. However, it can be overridden in the Order Line Item screen on a case-by-case basis. For example, if the customer and item typically allow back orders, then the Order Line Item back-orderable flag is set to "Y." But if the customer indicates that they would like to get what you have in stock and do not want the balance quantity back ordered, then you will set the "back-orderable" flag in the order line item to "N," and it will become "O/S" (Out of Stock).

Note that the following Global Setup flags in the Order Line Item Screen can also influence the line item "O/S" status:

    6. Close Out Order Ln Item When Not Fully Shipped? Default "N"
If you set this flag to "Y," then it implies that your business type does not allow back orders. Hence, all non-fully shipped order line items will become "O/S" (out of stock) upon billing selection. After the order is invoiced and posted, the line item will be closed out.

    33.. Warn/Prev BO When Customer Does Not Allow? Default "W"
Possible values are "W=Warning" or "P=Prevent." If the customer's "43. Backorder OK?" flag is set to "N" and the user overrides the line item to allow back orders, should the system give a warning message or prevent this from happening?