Solution : https://service.sap.com/sap/support/notes/77187 (SAP Service marketplace login required)
Key words : 
prerequisites solution implement note 73033, additional key words, production order, component quantity, possibly incorrect, material component, decimal places, alternative unit, correction
Related Notes : 
       
| 79149 | Alternative UoM: Incorrect adjustment of comp. qties | 
| 78687 | Wrong component qty when converting planned orders | 
| 73033 | Component quantity in production orders | 
| 51908 | Error when rounding in function module ROUND |