Solution : https://service.sap.com/sap/support/notes/578625 (SAP Service marketplace login required)
Key words : 
terms apo-atp-bop, update complete status, apo backorder processing, /sapapo/bop, backorder processing, /sapapo/bop_result, cave_sl_doc_inbound_bop reason, program error, solution implement, program corrections
Related Notes : 
       
| 628948 | Performance of BOP update in APO | 
| 578278 | BOP: 'Rejected' status | 
| 375193 | Backorder processing: Composite SAP note on posting |