Solution : https://service.sap.com/sap/support/notes/678397 (SAP Service marketplace login required)
Key words : 
prerequisites performance improvementyou implemented note 638441, simultaneous commitment updated based, performance reason, processing time, terms fmioi, solution implement, attached correction, references
Related Notes : 
       
| 640442 | Problems for ledger change or performance | 
| 638441 | Update termination during the saving of an order |