Solution : https://service.sap.com/sap/support/notes/120534 (SAP Service marketplace login required)
Key words : 
background processes operation mode index settings, processors db buffer size + size, additional key words emu, platform-dependent measuring errors, sun-os windows nt, database-specific system parameters, actual production data conversion, actual test conversion runtime, local currency changeover, multi processor machines
Related Notes : 
       
| 821868 | HWU: Runtime forecast deactivated | 
| 203069 | Cluster: no runtime forecast in production system | 
| 121626 | Euro LC changeover:important Support Packages info. | 
| 121245 | System settings for local currency changeover to euro | 
| 118011 |