Variability in Round-Trip Times for an Elevator Car During Up-Peak

The variability in the round-trip time of an elevator car is studied. Using the derived analytical expressions for the variance of round-trip time, we can evaluate the usefulness of solutions obtained from an optimization procedure in which round-trip time was assumed constant. Also, it is shown by numerical examples why passenger-carrying capability can be increased by operating a single bank of cars as two independent banks.