To record external service activities with service master data, you can confirm the activities in the Cross-Application Time Sheet (CATS) or create a service entry sheet. Service master data is a set of data that defines the scope and details of a service to be performed by an external vendor for a project activity. Confirming the activities in CATS is an action that records the time spent on performing external services and posts actual costs to the project. Creating a service entry sheet is an action that records the delivery of external services and posts actual costs to the project. Reference: https://help.sap.com/doc/0f069b2e08b748f1b480d4c8b46c3c49/100/en-US/6a7a9f0a6e421014e10000000a174cb4.html