Solution : https://service.sap.com/sap/support/notes/127133 (SAP Service marketplace login required)
Key words : 
document flow file vbfa, additional key words, prerequisites solution refer, attached advance corrections, billing documents takes, document involved, document processing, sales documents, symptom processing, large number
Related Notes : 
       
| 168829 | Performance doc flow, file VBFA (Shipping Statist.) | 
| 103218 | Performance of document flow, File VBFA |