Solution : https://service.sap.com/sap/support/notes/65906 (SAP Service marketplace login required)
Key words : 
set explicit preliminary settlement rules, master data maintenance screen, edit -> default distribution rules, enter distribution rules, preliminary settlement rules, system automatically settles, system automatically creates, line item apportionment, selected line item, line item settlement
Related Notes : 
       
| 398983 | Information: IM (Investment Management) | 
| 98801 | Transaction currency with settlement to fixed asset | 
| 74695 | Full settlement and periodic settlement to AuC |