Simulation modelling and analysis of order picking operations with mobile robots

With the development of technology and the increase in the number of companies in all markets, companies make various moves both to facilitate their supply chain processes and to stand out from their competitors. Warehousing is an essential part of a supply chain and it requires efficient management of warehouse operations such as receiving, storage, picking, packing etc. On the other hand, order picking is one of the most important operation for warehouses and it has a great impact on supply chain performance. Automation-based systems constitute an important part of the applications used to increase efficiency in order picking operations. Mobile robots are an essential component in automated systems and they provide ease of application in the workplace with its ability to corporate with humans. On the other hand, the efficient use of these robots is an important issue for companies since the initial cost is high. In this study, a hypothetical warehouse system of an e-commerce company is considered and the effect of mobile robots on order picking processes is investigated. In this context, simulation model of the system under-concern is developed using Arena software and analyzes are performed for various robot allocation policies. One of the most important aspects of this study is that it takes into account the charge levels of the robots. In the developed model, charge levels of the robots decrease depending on the distance they traveled and when the charge level of a robot drops to a certain value, the robot is directed to the charging station to be charged. Robot allocation alternatives are evaluated for mean flow time performance measure, and solutions are proposed for different system characteristics.