Elevator dispatching employing reevaluation of hall call assignments

An elevator car call is reassigned if a different car fortuitously shows up first, or if the assigned car leaves the group. The call is reassigned, one time only, if the assigned car is delayed by more than a threshold, or under certain circumstances, if the car is fully loaded without an intervening car call or the call has been waiting for more than a threshold time. The circumstances are that the weighted summation of membership values in fuzzy sets, indicating the degree to which the predicted waiting time for the currently assigned call is deemed long, the response time for a new call assignment is deemed small, and the improvement from switching the hall call assignment is deemed great, exceeds a threshold and each of the membership values exceeds its own corresponding threshold.