Solution : https://service.sap.com/sap/support/notes/526203 (SAP Service marketplace login required)
Key words : 
note groups summarizes, business information warehouse, terms psbw reason, consulting notes, ps content, prerequisites explanation, related notes
Related Notes : 
       
| 523741 | PSBW: Status in PS queries | 
| 494487 | Project System: Consulting notes | 
| 485067 | BCT-CO Delta DataSources: Simulation mode with Delta Init | 
| 454004 | PSBW: PROJ and WBSEL conversion exit | 
| 453630 | PSBW: Extraction of inheritance data | 
| 438207 | BCT-CO Delta DataSources: Extraction of quantities | 
| 429092 | PSBW: Extraction of orders and order costs | 
| 422541 | PSBW: Extraction of costs on activity elements II | 
| 421986 | PSBW: Performance problems when calling a PS query | 
| 416265 | BCT-CO delta DataSources: Technical background information | 
| 413992 | CO-OM Extractors: Data packet size | 
| 372771 | PSBW: Date extraction PS using GETWA_NOT_ASSIGNED | 
| 312927 | PSBW: Use of BW status concept in BW 2.0a | 
| 304483 | PSBW: Milestone trend analysis graphic | 
| 300300 | PSBW: Application of the status concept | 
| 215868 | PSBW:0PS_DAT_NAE and 0PS_DAT_NWA: Duration + Buffers | 
| 209200 | PSBW:Loading transaction data (requests) in 0PS_C01 | 
| 177995 | PSBW: Extraction of costs on activity elements |