Just In Time orders
Even if Ordering (1) is selected in the Create OE Back Orders At Stage field in SA Administrator Options-Documents-Sales Orders-Back Orders, back orders for orders with a disposition of Just in Time (JIT) are not created until the order reaches Picking (Stage 2).
When the back order is created, the original order maintains the JIT disposition. Because back orders cannot have a JIT disposition, the Disposition field on the back order is blank. You can change the disposition on the back order to another disposition.
The promised date and requested ship date on the sales order header comes from the previous order, back order, or release. The promised date and requested ship date on the line items are cleared if a back order is created.
For orders with a JIT disposition , the requested ship date on the Back Order Fill or Allocation report is the line date. For orders with any other disposition, the header date is used.