Solution : https://service.sap.com/sap/support/notes/535213 (SAP Service marketplace login required)
Key words : 
transportation planning/vehicle scheduling, goods issue date, delivery date, order items, backorder processing, edited items, oltp system, dates reason, problem occurs, solution implement
Related Notes : 
       
| 543687 | Incorrect scheduling data for main items | 
| 539643 | Confirmed schedule line is not created in the OLTP System | 
| 375193 | Backorder processing: Composite SAP note on posting |