Default cost center for service line items in ME21n/Me22n

Hi Experts,

Currently am working in a development to default the cost center based on line item of purchase order.

I have used the BADI ME_PROCESS_PO_CUST to default cost center for each and every line item based on requirement tracking number, and it is working fine.

But when am trying to create a service purchase order, i have to default the cost center in the service tab.

I didn't find any userexit or badi for the service line items in PO.

kindly help me to fix the issue.

Thanks,

Vijayan R.