To default the GL account while creating the Service PO’s, we need to follow the below configuration’s.
1. Create a Service Material Group in T-code OMSF.
2. Create a Valuation class by using T-code OMSK and then link to Account Category reference of service.
3. Use the T-code OMQW to map the Service Material Group (STEST) to Valuation Class (STES).
4. Once the above steps are completed , we need to use T-code :OBYC to map the valuation class STES to GL in Transaction Key GBB- Offsetting entry for inventory posting to the Account Modifier VAX,VBR and VKP. Also similarly to Transaction Key WRK-GR/IR clearing account with respect to your chart of account.
5. After that we have try to create a PO for the new service material group and it is defaulting the GL account which we have mapped in T-code: OBYC.
We can use the table T023 for Material Group mapping to Valuation Class and T030 for Valuation class mapping to GL account based on the Transaction Key and account modifier.
I believe this document is useful those who are new to SAP MM.