Recently we have done an External Service Management process for contract employees in integration with HCM module. This involves some development also, to automate the process. After successfully implementing the process, I just thought of sharing the experience with all my SCN colleagues, thinking that this may throw some lights on your similar kind of requirements.
My customer hires various services (like SAP Consulting) from different service providers (like IT companies). The contract employees (like consultants) are supposed to enter the time and the service provider will be paid based on the hours worked by the employees. The requirement is to automate the process and map this in SAP.
HCM module has been already implemented. A custom info type (9001) exist exclusively for contract employees which contains details like Service provider, contract terms etc.
The process starts with creation of Purchase requisition by user department.
To identify the employee, we have added the field PERNR (Personnel Number) in customizing,
Materials Management --> External Services Management --> Define Screen Layout
Now, the field Personnel number will appear in the PR and PO.
Purchasing department will create purchase order to the service provider.
In the custom info type for contract employees, a new field PO Number and PO Item is added. A program is developed to fetch all the Service PO created on that day and scheduled it in background to run every night. Also, the program picks the PERNR from ESLH and ESLL tables and for that PERNR, it updates the custom info type table (PA9001) with this PO number and item.
Now the contract employee fills his working hours in CATS time sheet. Once the time sheet is approved, a scheduled job will fetch the personnel number from time sheet. From the info type table, the program will fetch the PO number and item and create a Service Entry Sheet, using the BAPI BAPI_ENTRYSHEET_CREATE.
A subsequent job for standard transaction ML85 (Program RMSRVF00) releases the Service entry.
Once the service entry sheet and material document is posted Finance department can do invoice verification ate month end for the accepted quantity and pay the vendor. We are planning to automate the invoice verification also, once the process gets stabilized.
This is just my experience in addressing the said requirement. Expecting your valuable feedback and suggestions. Also request you to share your experiences in addressing similar requirements, if any.