A performance model for mobile robot-based part feeding systems to supermarkets

Abstract

In a context where companies are striving to produce highly customised goods in small batches and within short lead times, increasing attention is being put on the design and management of part feeding systems. This research is the first to model automated part feeding to supermarkets in a factory environment, considering an innovative technology called vertical robotic storage and retrieval systems. This technology allows automating the storage, picking, and internal transportation activities in an integrated process, thanks to rack-climbing robots roaming in both the shop floor and the storage racks. We develop an analytical model based on the queuing network approach to analyse the system performance, and we use it to perform numerical experiments and to evaluate the design trade-offs with reference to a real case in the automotive industry. Results show that an increase in the number of robots leads to better performance since the positive impact on the response time is stronger than the negative impact on the waiting times of robots at the supermarkets due to congestion. Furthermore, a configuration with multiple small supermarkets improves the efficiency of the replenishment process, compared to a setting with few big supermarkets.

Unleashing Industry 4.0: Leveraging Lean Practices to Overcome Implementation Barriers

“…Vertical integration merges several hierarchical subsystems to establish a flexible and changeable production system [31]. Through end-to-end engineering integration, customized goods and services may be produced at every value chain stage [42], [43].…”

A Simulation Analysis of Part Feeding to Assembly Stations with Vertical Robotic Storage and Retrieval Systems

“…the number of totes that can be stored in each supermarket, and the number of robots, N R , needed to fulfill all the replenishment orders. Once fixed the number of supermarkets, S s determines space occupation in the shop floor, where space is a critical resource, while robots are the main component of the investment in this system [14]. Thus, the first experiments are aimed at studying the relationship between these two variables.…”

“…This system has been studied in literature in relation with distribution centers only by [13]: they develop a queuing network-based model of VRSRS, but they neglect the possibility for robots to navigate outside the racks. Only one contribution has addressed the deployment of VRSRS in a factory environment [14], but it models the replenishment of supermarkets from the central warehouse, without considering the transportation of totes to assembly stations. This research aims to assess the performance of a part feeding system to assembly stations based on VRSRS.…”