In large organizations users frequently move from project to project or department to department. When this happens, users need access to new resources - typically files, folders, printers and mail distribution lists.
Most business users understand these resources, but not the security infrastructure that allows some users but not others to access them. Consequently, they call the help desk, asking for something ambiguous: "I need access to the printer in the corner" rather than something actionable: "I need to join group X on AD domain Y."
The ambiguity that arises in communication between business and technical users slows down the change control, introducing frustration, cost and delay.
Group Manager translates user requests to "IT language" and automatically follows through with an approval work-flow and fulfillment. Users get better service and IT is able to focus on higher priority tasks.