Solution : https://service.sap.com/sap/support/notes/31557 (SAP Service marketplace login required)
Key words : 
-> sap library-> mysap technology components-> cross-application functions-> client conceptsee, /support -> problem solving -> sap notes -> note number 31557, -> sap library-> expand topic sap netweaver, -> expand cross application services-> client conceptor, special cross-client authorization, theservice marketplace / support portal, cross-client customizing settings, mysap solutions parallel processing, prevents individual customers/clients, daily business processes entered
Related Notes : 
       
| 1564115 | Deployment of SAP Best Practices | 
| 557132 | CC-TOPIC: Remote client copy | 
| 552711 | FAQ: Client copy | 
| 550894 | CC-ADMIN: Setting up a new client | 
| 489690 | CC INFO: Copying large production clients | 
| 395358 | Multiple client capability of IS-OIL/IS-MINE | 
| 175293 | HR-PDC multiple-client capability | 
| 67205 | CC-INFO: Copying large and productive clients | 
| 64520 | Question on client dependency R/3 - R/2 | 
| 39472 | Country-specific customizing for several countries | 
| 31496 | CC-INFO: Client deleted by mistake | 
| 24853 | CC-INFO: Client copy, functionality | 
| 1201 | SAP-SQL for all clients |