Solution : https://service.sap.com/sap/support/notes/71543 (SAP Service marketplace login required)
Key words : 
additional key words, order / wbs element, transaction kob5 / cj70, line items developed, line item settlement, 0 line item settlement, line items, transaction aiab, wbs elements, investment measure
Related Notes : 
       
| 303741 | Final sttlmnt/inv.measure: Amount in settlement rule not pos | 
| 147922 |