Solution : https://service.sap.com/sap/support/notes/899011 (SAP Service marketplace login required)
Key words : 
account price purchasing group goods receipt processing time planned delivery time currency, edit pm/cs orders, alm- bapi downgrade kit, purchasing data, terms resbd-webaz, bapi_alm_order_maintain bapi, bapi reason, resbd-ekgrp, resbd-lifzt, resbd-peinh
Related Notes : 
       
| 872340 | BAPI: Non-stock material cannot be entered | 
| 861682 | Relevancy for planning set incorrectly in the PM/CS order | 
| 768792 | RESB-MATKL blank after changing component | 
| 708508 | Downgrade BAPI_ALM_ORDER_MAINTAIN -> errors |