BSR -Basic Schedule Rate or Model Service Specification (MSS)
The process illustrate to make entry of Model Service Specification (MSS) or BSR in SAP MM Module. The Tcode ML10 may be taken for such BSR entries. You have to enter BSR name and category of BSR into system.
Then in the next screen you can enter long text of BSR as description.
Enter all the relevant service activity code, quantity and rate. Here in the same screen you can add condition of above or below in % if required.
After this process you can use the same BSR into creation of PR (Purchase requisition) so that will save a lot of time for creating multiple PR for same services.