Solution : https://service.sap.com/sap/support/notes/87004 (SAP Service marketplace login required)
Key words : 
additional key words component supplier processing, calculating total order quantity/, forecast delivery schedule, jit delivery schedule, release date, existing release, original date, saved separately, separate field, program error
Related Notes : 
       
| 109189 | SIS comp. supplier:Incoming order may be too high | 
| 81335 | Incoming order for sched. agreements not correct |