Dispatching of an electric monorail system: Applying metaheuristics to an online pickup and delivery problem

In this article we present a new solution approach for a specific online pickup and delivery problem as it occurs in a real-world dispatching task of electric monorail load carriers. The presented optimization module adapts the communication structure of the respective IT components of the warehouse system to facilitate an easy integration. Numerical results are presented comparing steepest descent as well as reactive tabu search and simulated annealing with the dispatching system used so far. Tests are performed on the basis of a detailed simulation model of the entire warehouse and show a clear superiority for this approach.