Solution : https://service.sap.com/sap/support/notes/109671 (SAP Service marketplace login required)
Key words : 
additional key words xvbep_zuordnen, system determines requirements incorrectly, prerequisites apply note 101342, attached advance corrections, confirmed schedule lines, system creates, schedule lines, schedule line, sales order, previous item
Related Notes : 
       
| 129470 | Incoming orders for component suppliers: Alternative update | 
| 121509 | Comp.suppl.proc.: Open delivery qties incorrect | 
| 118880 | SIS comp. sup:Incom ord may be too high a. N.109189 | 
| 109189 | SIS comp. supplier:Incoming order may be too high | 
| 101342 | Performance during rescheduling |