Scenario for 1st&2nd services: When the SRM central contract created with the distribution maintained in it, then service “PurchasingContractSRMReplicationRequest_Out” fired from the SRM to ECC. Which helps in replication of the central contract in the ECC. Depending on the distribution maintained, service fired to more than one ECC system. In turn, service “PurchasingContractSRMReplicationConfirmation_Out” fired from the ECC to SRM. Which notifies the SRM about the contract replication.
Scenario for 3rd service: When central contract is used has source for the creation of purchase order,
Service “PurchaseOrderERPContractReleaseNotification_Out” fired from ECC to SRM to update the release value in the contract.