Active repositioning of storage units in Robotic Mobile Fulfillment Systems

TL;DR

This paper introduces mechanisms for active repositioning of storage units in robotic mobile fulfillment systems, aiming to improve inventory management and efficiency through simulation-based experiments.

Contribution

It presents the first mechanisms for active pod repositioning and evaluates their impact via simulation in e-commerce fulfillment centers.

Findings

Active repositioning can improve storage efficiency.

Simulation shows potential for increased pick rates.

Passive repositioning remains effective during operations.

Abstract

In our work we focus on Robotic Mobile Fulfillment Systems in e-commerce distribution centers. These systems were designed to increase pick rates by employing mobile robots bringing movable storage units (so-called pods) to pick and replenishment stations as needed, and back to the storage area afterwards. One advantage of this approach is that repositioning of inventory can be done continuously, even during pick and replenishment operations. This is primarily accomplished by bringing a pod to a storage location different than the one it was fetched from, a process we call passive pod repositioning. Additionally, this can be done by explicitly bringing a pod from one storage location to another, a process we call active pod repositioning. In this work we introduce first mechanisms for the latter technique and conduct a simulation-based experiment to give first insights of their effect.