Solution : https://service.sap.com/sap/support/notes/357400 (SAP Service marketplace login required)
Key words : 
additional key words main item, attached source code corrections, respective main item, rule-based atp, apo release 30a, cif integration model, sales orders carried, integration model, sales orders, /3 sales documents
Related Notes : 
       
| 445032 | Performance APO initial transfer sales orders | 
| 392045 | APO performance initial data supply of sales order | 
| 391780 | Delta report: Long runtime for sales order comparison | 
| 389618 | Composite Note: APO initial data transfer with sales orders | 
| 387706 | Initial supply of APO with sales orders | 
| 387699 | Initial supply APO sales orders | 
| 385800 | Error in initial data supply of sales orders | 
| 375193 | Backorder processing: Composite SAP note on posting | 
| 371396 | Update of BOP results | 
| 365424 | Incorrect updating of APO backorder processing in R/3 |