Purchase Order: Queries related to Service Entry Sheet (ML81N)

Question

Requirement:
   A user exit to be trigger during the changing (update) of service entry sheet, This user exit should have a code which will go and check the credit memo in RSEG- SHKZG where the value is “H” and will check RSEG- LFBNR number with ESSR-LBLNI and compares RSEG- SHKZG with ESSR- NETWR value of the service entry sheet. if the value is less then or more then ESSR- NETWR (service entry sheet) value it should throw an error “"Amount must equal Service Entry”.
If the RSEG- SHKZG value and ESSR- NETWR value are equal it should allow to revoke the service entry sheet. 
Scenario: When user clicks on Change button in ML81N for changing the Service Entry Sheet(existing one), an exit should trigger the error message and should not allow to change.
Please suggest how to achieve it, which Exit to use where I should code?

Answer 1

Hi Amol
Why you created Framework Order ?.. You can not change account assignment category in service entry sheet..e.g. K-Cost Center.. F- Order
But depending upon settings, you can change account assignment values such order 1 to order 2
If there are requirement that SES can created for  Account assignment F or K. I recommend you to use following approach
1. Create a Contract - ME31K with AAC as U- Unknown (If business already have rates negoiated with vendor for services)
2. Create release order with reference to contract and system will prompt you to enter AAC- it can be K or F
3. Perform SES w.r.t to Release Order.
Other Approach can but not strong one.. create two line items in the PO. one with K and Other with F.. then choose the line item at time of SES creation that business want to book the cost on CC or Order.
Thanks,
Jagdeep