For what I do:
System Ride Time is calculated from initial dispatch to where automatic block advancing ends. This the point where an operator must acknowledge the advancement of a train and not the logic controls performing a zoning function.
Functional Ride Time is calculated as a full cycle. This includes the three basic functions of holding, loading and unloading. The loading and unloading uses the time standard for the seating arrangement of the trains. In most cases we shoot for 45 seconds to be in "Ready for Dispatch" state.