I have seen several demo's from ESRI where they show a street network and either EMS vehicles or police. The user clicks on a vehicle and types in a time value in a dialog and it will show a polygon of how far that vehicle can cover based on the road network (factors in speed limits of road) etc. This way you can see the coverage and how far out a vehicle is etc.
I was thinking...instead of a road network what if it was a transmission line network. Instead of a vehicle what if the user clicks a substation location. Then when the relay group tells us there is a fault from Substation XYZ and it is 4 miles from said sub it will show us all the locations that are 4 miles away on any circuit coming out of that substation.
