Optimal unit-load warehouse designs for single-command operations

We present a continuous space model for travel in a unit-load warehouse that allows cross-aisles and picking aisles to take on any angle. The model produces optimal designs for one, two, and three-cross-aisle warehouses, which are called chevron, leaf, and butterfly designs. We then use a more accurate discrete model to show which designs are best for a wide range of warehouse sizes. We show that the chevron design, which is new to theory and to practice, is the best design for many industrial applications.