Solution : https://service.sap.com/sap/support/notes/305806 (SAP Service marketplace login required)
Key words : 
additional key words subsequent settlement, price determination calculates 200 kg, volume-based rebate, attached program correction, subsequent settlement provided, 200 kg yields 6 dem, 1 kg = 20 frf multiplied, condition currency deviates, price determination, subsequent settlement
Related Notes : 
       
| 183379 | Composite SAP note subsequent settlement (Purchasing) 4.6 | 
| 152725 | Collective note: Subsequent settlement (Purch.) Release 4.5 | 
| 104668 | Collective note: Subsequent settlement (Purch.) Release 4.0 | 
| 40147 | Collective note: Subsequent settlement (Purch.) Release 3.0 |