Solution : https://service.sap.com/sap/support/notes/434532 (SAP Service marketplace login required)
Key words : 
availability check, dynamic assembly, finished product, terms config, va02 reason, solution implement, source code, prerequisites note 418767, note 450154, configuration
Related Notes : 
       
| 450154 | Dynamic assembly: Assembly order cannot be adjusted | 
| 418767 | Dynamic assembly: BOM not exploded |