Solution : https://service.sap.com/sap/support/notes/418443 (SAP Service marketplace login required)
Key words : 
transport planning / vehicle scheduling, additional key words transaction, prerequisites solution repair, desired delivery date, delivery date, loading date, order items, order item, correctly processed, /sapapo/bop
Related Notes : 
       
| 417525 | Backorder processing: Delivery scheduling in TP/VS | 
| 416762 | Backorder processing: TP/VS scheduling incomplete | 
| 408885 | Backorder processing: TP/VS scheduling ignored | 
| 402505 | Backorder processing: Loading date not taken into account | 
| 399301 | Backorder processing: Loading date not taken into account | 
| 375193 | Backorder processing: Composite SAP note on posting |