Injecting speculation on ideal trajectories into a trip-based integer programming model for elevator operations

In this paper, we propose a technique for a trip-based integer programming model for elevator operations to decrease computational times in solving problems for multiple elevators. The technique is inspired by the speculation on ideal trajectories of elevators, where the interval of arriving floors is equal to each elevator. Such trajectories are regarded as oscillating waves. It is expected that limiting movements of elevators to resemble such waves may decrease computational times without degradation on the objective value. This expectation is numerically examined by obtaining optimal trajectories of some problem instances.