Solution : https://service.sap.com/sap/support/notes/432661 (SAP Service marketplace login required)
Key words : 
symptom error analysis requires debugging flow control services, prerequisites error analysis requires debugging flow control services, flag indicating debug mode, flow header structure smw3_fhd, flow service function modules, asynchronous trfc/qrfc step, flow control, asynchronous step reason, choose function retry, calling cl_smw_mflow=> process_outbound
Related Notes : 
       
| 591691 | |
| 536414 | CRM 3.0/3.1 SAP Composite Note: Middleware reorganization |