Solution : https://service.sap.com/sap/support/notes/421358 (SAP Service marketplace login required)
Key words : 
radio button 'remote-enabled module', additional key words transaction, function module /sapapo/bop_buffer_alert_clear, short text 'initialization, /sapapo/bopbackorder processing, solution implement note 421072, source code corrections, function module, source code, transaction se37
Related Notes : 
       
| 609435 | Composite SAP note: Performance in backorder processing | 
| 421716 | Backorder proc.: Writing of the queue waits for alerts | 
| 421072 | ATP->VS: Sub-orders in //APROF_GET_VS read twice | 
| 420605 | Composite SAP Note for BOP performance in APO 3.0A | 
| 392745 | Standardization BOP, BOP_VS functions | 
| 375193 | Backorder processing: Composite SAP note on posting | 
| 370601 | Composite SAP note: APO 3.0 and 3.1 performance |