Crane and shuttle optimization in warehousing systems

We consider a modern warehousing system composed of a number of aisles, each one is served by a crane and sided by a pair of racks, and a shuttle charging one unit load at a time moves along a mono-dimensional path placed orthogonally with respect to the aisles axis. Two control algorithms to optimize the operations of the cranes (moving within the aisles of the warehouse) and the operations of the shuttle (moving on a straight line placed between aisles and the picking/refilling area) respectively, are proposed. To evaluate the performance of the proposed control algorithms we define three different cost indices: the first two indices look to the crane/aisle and shuttle areas as they were independent systems, while the third index measures the performance of the whole warehousing system. Finally, extensive simulations are performed on the model developed by Basile at al. (2001) to show the effectiveness of the proposed control algorithms.