Solution : https://service.sap.com/sap/support/notes/332401 (SAP Service marketplace login required)
Key words : 
attached source code correctionsbefore, additional key words transaction, reference type /sapapo/c_traty, component type /sapapo/rrflg, component type /sapapo/surea, source code corrections, call transaction se37, call transaction se11, prerequisites solution implement, 'import' tab page
Related Notes : 
       
| 400517 | Backorder processing: Deadlines are not transferred | 
| 375193 | Backorder processing: Composite SAP note on posting | 
| 321913 | Transfer of the backorder processing results | 
| 321909 | Structure - results of backorder processing |