What Windows service needs to be running in order to get the health metrics for SiteServer and Work Manager?
From UI, Work Manager, or Site Server we were calling into a windows API called WMI, which in turn talks to the service Windows Management Instrumentation (Winmgmt). This service should be there by default on any windows install. And by default this service should be running or starts automatically on startup.
The health metrics can be viewed in the UI under Management >> Site Server Console or Management >> Work Manager Console.