Deterministic Structure of Vertical Configurations in Minimal Picker Tours for Rectangular Warehouses

Abstract: The picker routing problem involves finding the shortest length tour of a warehouse that collects all items in a given pick-list. In this work, we demonstrate that in a rectangular warehouse, the horizontal structure of a minimal tour subgraph can be used to determine the required vertical edges. This result directly reduces the number of stages in the dynamic programming algorithm for warehouses with one or two blocks.