Hi Rohan,
The Concept of Pre-DME and DME comes after the payroll result are posted to FI module to make the payment.
In order to transfer the data to the employee house bank for making payment we run Pre-DME and DME program.
First you have to process Pre-DME program (PC00_M40_CDTA) , this program will updated the BT Table for the payment to employees. It updates three Table ( REGUV, REGUH and REGUP).
Then you have to run the DME Program (PC00_M40_FFOM), this program will provide all the information to the house bank that needs to transfer the wage and salary payment to the employee.
Hope this will help you.
Thanks & Regards
Saroj Hial