Double Traversals in Optimal Picker Routes for Warehouses with Multiple Blocks

TL;DR

This paper proves that in warehouses with multiple cross-aisles, double traversals within subaisles are unnecessary for optimal picker routes, simplifying route planning and enabling more efficient algorithms.

Contribution

It extends previous knowledge by showing double traversals are not needed in warehouses with more than two cross-aisles, simplifying route optimization.

Findings

Double traversals are unnecessary in warehouses with multiple cross-aisles.

Simplifies the structure of feasible picker routes.

Enables more efficient route planning algorithms.

Abstract

Order picking is a process that involves collecting items from their respective locations within a warehouse. There exist dynamic programming algorithms for finding the minimal picker route by considering only a limited number of options for possible travel within a subaisle. Although one such action, traversing an aisle twice, has been shown to never be required for a rectangular warehouse with two cross-aisles, this is not the case when there are more than two cross-aisles. In this work, we demonstrate that double traversals within a subaisle are not required to connect cross-aisle travel regardless of the number of cross-aisles. This result simplifies the structure of feasible tours, enabling more efficient algorithms.