The goal milestone in a service level defines:

The goal milestone in a service level is specifically designed to establish the time frame within which a case or step is expected to be completed. This ensures that processes remain efficient and that service levels are met. By defining this time frame, it sets clear expectations for both the service provider and the client regarding how quickly tasks should be executed. When service levels are closely monitored using goal milestones, organizations can ensure timely progress in their operations and enhance overall performance.

While other options relate to time management in different contexts, they do not accurately capture the essence of what a goal milestone represents within the service level framework. A goal milestone focuses on target completion time, making it a pivotal aspect of managing and measuring service levels effectively.