A comprehensive framework for the design of modular robotic mobile fulfillment systems

Abstract

This paper focuses on the design of modular Robotic Mobile Fulfillment Systems. A Robotic Mobile Fulfillment System is an automated storage and retrieval system, in which mobile robots are deployed to deliver storage shelves for picking operation. This paper proposes a modular robotic system with aisle-captive robots for small and medium-sized logistics warehouses. Then analytical models, including a bottleneck-based model and an open queueing network model, are developed to estimate system throughput and average order flow time. Last, a two-stage design framework is proposed to rapidly identify an optimal system configuration. The main contributions are that: first, the proposed modular robotic system is free of traffic congestion and blocking; second, the comprehensive framework highlights some significant guidelines for warehouse developers during the 'conceptualization' phase of system development. Simulation experiments indicate that the open queueing network model can provide accurate system performance estimation. The effectiveness of the proposed design framework is validated through practical application in real cases.