Abstract: An elevator system, and method of operating same, having a plurality of elevator cars for serving hall calls registered from the floors of a building. All of the up and down service directions from the floors are continuously assigned to the elevator cars, whether or not they have an active registered hall call associated therewith, with the assignments being made according to predetermined averages which uniformly spread the actual and prospective work loads among the elevator cars. The hall calls are timed. A timed-out call, i.e., a call registered for a predetermined period of time, is given preferential treatment, without significantly disturbing service to other registered hall calls, by assigning the floor and service direction associated with the timed-out call to an additional car which is not already assigned to a timed-out call. The additional car is selected on the basis of its having the lightest work load schedule of all of the elevator cars conditioned to serve the timed-out call.

Abstract: An elevator system having a plurality of elevator cars and supervisory control for directing their movement in a building to efficiently serve the floors therein. The supervisory control divides the floors and service directions therefrom, called scan slots, into sets, with a set being those scan slots served by the same combination of cars. The scan slots are assigned to the elevator cars using a predetermined strategy, with the sets being taken in a predetermined order determined by the number of cars enabled to serve the sets. The strategy breaks out of the rigid set concept when assigning scan slots to cars based upon car calls, to effect a significant improvement in elevator service.