Patent 7510054 was granted and assigned to Otis Elevator Company on March, 2009 by the United States Patent and Trademark Office.
When an average wait time is low (23, 24) an elevator car (31-34) is parked (39), unable to answer calls, or if a parameter (45) is low (46), the car is shut-down. If wait time is high, a parked car is assigned the call. If no cars are parked, a shut-down car may be assigned based on RRT. If up running cars can answer the call, the down running cars are excluded.