Solution : https://service.sap.com/sap/support/notes/507740 (SAP Service marketplace login required)
Key words : 
internal business volumenow create, internal business volume, internal business volumeimplement, source code correction, symbol = 090   text   = rpsco, internal order, text symbol, short text      =, plan settlement, system displays
Related Notes : 
       
| 388130 | Costs of networks from archives | 
| 336544 | PS-IS: Overall plan in PS hierarchy reports |