Solution : https://service.sap.com/sap/support/notes/70643 (SAP Service marketplace login required)
Summary : 
      SAP Note provides guidance on efficient client deletion in SAP systems. To delete a client, the recommended method from SAP Release 3.0 is through SCC5 transaction, unless performance or stability issues dictate otherwise. R3trans with 'clientremove' remains viable for particular scenarios, such as prior to usage of SCC5 or for systems with large, low number clients, as explained in SAP Note 365304. Issues may include unauthorized access errors, insufficient memory release post-deletion, or excessive time taken for deletion, particularly in Release 4.6. Solutions involve using SAP* user for deletions and applying Basis Support Packages or advance corrections noted within the document for optimizing the deletion process.
Key words : 
call_function_remote_error   call_function_signon_rejectedthe table processed, case unnecessary database access, additional key words scc5, basis support packages include, basis support packages, full table scan, avoid ressource problems, initial password pass, initial user sap, initial sap user
Related Notes : 
       
| 365304 | CC-ADMIN: Reports for deleting tables | 
| 208919 | CC-INFO: Performance as of Release 4.6 | 
| 206523 | CC-RELEASE: Client copy errors in 4.6C and 4.6D | 
| 161495 | CC-RELEASE: Error in client copy in 4.6A and 4.6B | 
| 96296 | CC-ERROR: Database problem in client copy | 
| 67205 | CC-INFO: Copying large and productive clients | 
| 38747 | SAPDBA: Option "reduce object size" | 
| 35952 | Client deleted, space still filled in database | 
| 24853 | CC-INFO: Client copy, functionality | 
| 22941 | Reorganization of tables and dbspaces! | 
| 19574 | CC-ADMIN: Controlling data selection during client copy |