Solution : https://service.sap.com/sap/support/notes/402247 (SAP Service marketplace login required)
Key words : 
'vm' mrp type, 'x0' mrp type, reorder point planning, initial planning, initial transfer, terms rimodact, missing functions, solution maintain, source code, correction transfers
Related Notes : 
       
| 520561 | Maintaining product master in R/3 or in APO? | 
| 456460 | Change transfer for fields of the material master |