Introduction
With the rapid growth of e-commerce, efficient automated warehouse storage and retrieval systems have become essential. This study explores the integration of a Vertical Lift Module (VLM) with a shuttle-based storage and retrieval system (SBS/RS) to address storage limitations and improve order-picking efficiency.

VLMs are automated warehouse storage systems that utilize vertical space, while SBS/RS provides a dynamic buffer for inventory management. The research aims to evaluate the performance of this hybrid system using AnyLogic simulation software, focusing on throughput, cycle time, and system order-picking efficiency.
Check out other academic papers about Vertical Lift Modules or business case studies about automated warehouse systems.
Simulation model
The study utilizes AnyLogic as the primary simulation tool due to its ability to combine discrete-event and agent-based simulation modeling in a single framework. Discrete-event is used to model sequential processes such as tray retrieval, shuttle movements, and efficient order-picking, ensuring precise tracking of automated warehouse storage system performance. Agent-based modeling captures individual behaviors of shuttles, operators, and inventory units, allowing for a more dynamic and scalable representation of the system.
AnyLogic's flexibility in multimethod modeling enables seamless integration between the VLM and SBS/RS, ensuring realistic interaction between components. The visualization capabilities provide a clear representation of tray movements, inventory transfers, and order fulfillment processes. Key parameters, such as shuttle speed, lift acceleration, and storage capacity, are configured within AnyLogic to test different system scenarios.
The simulation model can run multiple experimental configurations to compare the performance of a standalone VLM against the integrated VLM-SBS/RS system.
Results
The research indicates that integrating a buffer enhances automated warehouse storage system capacity and improves inventory management. Higher velocity profiles lead to increased throughput, reducing order cycle times. However, diminishing returns are observed beyond a certain speed threshold. The hybrid system improves order-picking efficiency and reduces operator workload but requires further optimization in replenishment strategies and order sequencing.
Future research will explore additional configurations, including multiple lifts and dynamic storage allocation, to maximize system performance.