Solution : https://service.sap.com/sap/support/notes/78935 (SAP Service marketplace login required)
Key words : 
command 'set update update task local' -, additional key words ale, source code change, symptom idocs, updated repeatedly, recipient system, status list, prerequisites precondition, inbox processing, called repeatedly
Related Notes : 
       
| 118924 | Parallel processing of IDocs in the POS inbound | 
| 105604 | |
| 78757 | SET UPDATE TASK LOCAL | 
| 74777 | ALE/EDI:BD87 IDocs can be imported several times | 
| 70961 | EDI/IDoc: Inbound sporadic errors DUPREC EDIDS. |