Solution : https://service.sap.com/sap/support/notes/139124 (SAP Service marketplace login required)
Key words : 
net indicator set, additional key words, order header quantity, production order, assembly scrap, operation scrap, longer matches, source code, solution correct, maintained
Related Notes : 
       
| 377648 | Incorrect requiremt quantity after header change in quantity | 
| 363865 | Assembly scrap for dummies | 
| 210454 | COMPUTE_FLOAT_ZERODIVIDE w.insertng ref.operatn set |