Account determination for material group
I am configuring account determination for material groups. What I have seen is that I can have one G/L account determined per material group depending on the valuation class assigned to the material group. Now this G/L acount also varies according to the account assignment category assigned in the PO. The system basically picks the consumption account in OBYC assigned to GBB - XYZ combination where XYZ is the account modifier asigned to the account assignment category in the PO.
Now what my client wants to understand is that why is it so that in SAP, G/L account determination depends on account assignment category in PO like sales order (E), project (Q or N), cost center (K) etc. What is the business logic for this?
They want to determine G/L accounts depending on whether a material/service is procured internally (from a group company) or externally (from an external vendor). Is this possible in SAP standard way?