An analytical approach for the performance calculation of an RCS/RS with several picking stations

Abstract

Robotic Compact Storage and Retrieval Systems (RCS/RS) offer numerous advantages, including high performance, scalability, and availability, which are essential for modern logistics and warehousing. However, information on the potential performance of RCS/RS is limited, primarily due to the diverse range of configurations available. This paper aims to address this gap by developing an analytical approach to predict the throughput of an RCS/RS with multiple robots serving several picking stations. The approach considers various parameters such as grid size, stack height, number of robots, and filling degree, alongside kinematic data. The cycle time for each robot is calculated assuming a uniform distribution of container stacks. Subsequently, a queueing system with limited capacity is constructed using performance data from a single robot. The analytical approach is validated using a discrete event simulation model of an RCS/RS. Following the validation, an extensive parameter variation and application example are conducted to demonstrate the versatility of the approach. This method offers a straightforward and efficient set of formulas for determining RCS/RS throughput, easily solvable using standard table or algebra programs.