Solution : https://service.sap.com/sap/support/notes/500966 (SAP Service marketplace login required)
Key words : 
customer reports missing data, effective pre-analysis, sap service employee, pre-analyzed correctly, bw standard display, business-relevant fields, bw standard system, data package number, data returned, data records
Related Notes : 
       
| 592366 | BCT-IM: Performance optimization when reading from PSA | 
| 398041 | INFO: CO-OM/IM-Content (BW) | 
| 371760 | BCT-CO delta DataSources: preanalysis of (perform.) | 
| 365762 | Loading data: Pre-analysis of (performance)problems | 
| 316718 | BCT-IM: Preconditions for InfoCube update 0IMFA_1 |