Solution : https://service.sap.com/sap/support/notes/153205 (SAP Service marketplace login required)
Key words : 
additional key words deleting work items, work item ct - creation time, work item commitc - number, cd - creation date, work item types, work item id, standard report rswwwide, attached report rswwcide, reports rswwwide/rswwhide, idoc inbound processing
Related Notes : 
       
| 737696 | Add. info on upgrade to SAP R/3 Enterprise 4.70 Ext. 2 SR1 | 
| 637683 | Add info about upgrade to SAP R/3 Enterprise Core 4.70 Ext 2 | 
| 587896 | Add. info on upgrade to SAP R/3 Enterprise Core 4.70 SR1 | 
| 573656 | Collective note relating to Archiving in workflow | 
| 420371 | Add. info on upgrading to Basis 4.6C SR2 (NDI upgrade) | 
| 390062 | Additional information about upgrading to 4.6C SR2 | 
| 329622 | Additions: Upgrading to Basis 4.6C SR1 (NDI upgrade) | 
| 327285 | Additions to upgrade to 4.6C SR1 | 
| 304597 | Additions to upgrade to Release 4.6C FCS | 
| 192949 | Additional info for upgrade to 4.6C | 
| 179373 | Additional info for upgrade to Rel.4.6B | 
| 155674 | Additions upgrade to Release 4.6A | 
| 126678 | Archiving or deleting work items of type C | 
| 49545 | Deleting unnecessary work items |