The term 'back order' has different meanings to different people. When people where using paper for order entry and the order could not ship complete, a new order called a Back Order would be created with the remaining items and quantities therein recorded. Older ordering systems only allowed one shipment against one sales order however this is not the case with All Orders. When a sales order does not ship complete it simply remains open until all the orders are shipped or cancelled. Therefore in All Orders a back order is an order that has not shipped complete AND that is beyond the due date. A back order DOES NOT necessarily mean that you are out of stock of a particular item it simply means that the item has not shipped by the due or promise date.
As an example consider the following sales order that was created November 11, 2008 and has a due date of November 4, 2008. Note the back order column is highlighted in yellow.
By changing the due date the back order column is set to 0.
A really great way to track back orders is to customize the Sales Order by Item report. I created a new report called 'Back Orders'. I then went to the filter tab and added Back > 0. I click 'Saved Filter' so i would not need to add the filter each time I ran the report then I clicked the file icon to save the report.
When I run the report I see sales order by item that have a back order.