Users need to maintain External System information in SAP Ariba Strategic Sourcing, which corresponds to the Logical System ID of your back-end SAP ERP or SAP S/4HANA (on-premise). This configuration is required when uploading Master Data, and the correlation of System ID and Master Data is used when creating Quote Messages (Award), and Contracts.
The following simulation will walk you through the steps to maintain the External System in SAP Ariba Sourcing: