Browsing by Author "Tutam, M."

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Designing Unit-Load Warehouses: Use Deterministic or Probabilistic Models
(Institute of Industrial and Systems Engineers, IISE, 2021) Tutam, M.; Liu, J.; White, J.A.; Liao, H.
Designing a warehouse can be quite challenging because of the variability and uncertainty of operations performed. Although deterministic models can be developed and solved easily, they do not capture the random variation inherent in travel distances. In determining the optimal shape of a unit-load warehouse, will the designs be different if the shape is determined to minimize the average travel distance versus minimize the expected number of requests for storage and retrieval (S/R) waiting or being served? To answer this question, we compared the optimal shape factor and resulting expected travel distance for a multi-dock, unit-load warehouse under a new dwell-point policy. Compared to previous research, the performance of the system is increased approximately nine percent by using a specific dwell-point policy for S/R equipment. The impact of minimizing the variance of travel time on the optimal warehouse shape was also examined. Although queueing model provide additional information, the optimal shape factor for unit-load warehouse based on deterministic analysis is not significantly different from the optimal shape factor based on probabilistic analysis. © 2021 IISE Annual Conference and Expo 2021. All rights reserved.
Performance Analysis of a Class-Based Robotic Compact Storage and Retrieval System
(Institute of Industrial and Systems Engineers, IISE, 2023) Tutam, M.; Liu, J.; White, J.A.
Warehouses are often characterized by low cube utilization, which becomes an issue with land scarcity and increasing land prices. Robotic Compact Storage and Retrieval Systems (RCS/RS) have been developed to increase space utilization. They do not require traditional picking- and cross-aisles. In such a system, a grid-based storage space contains bins stacked on each other. Moreover, robots operate on the roof of the system to lift or lower bins in stacks while transporting them between storage locations and ports. The question is what the dimensions of an RCS/RS should be because operation times for the system differ based on the speed of robots, as well as the x-, y- and z-dimensions and the number of bins. To minimize the expected operation time of a robot to complete storage/retrieval operations, we embed a discrete formulation of the generalized assignment problem in an enumeration over the z-direction to determine the optimum allocation of bins to locations in a three-dimensional class-based storage space and the best dimensions of an RCS/RS with the proposed algorithm in a reasonable time frame. We consider three classes of bins based on different skewness values for activity levels. Our optimization model can be used to design a new RCS/RS or analyze an existing RCS/RS based on its current system parameters. © IISE and Expo 2023.All rights reserved.
Pharmaceutical Warehousing 4.0 in Healthcare Supply Chain
(Springer Nature, 2023) Tutam, M.
Over the last decade, many countries have suffered from supply chain disruptions for different products because of the ever-increasing global problems with devastating financial and social consequences. In response, most companies revisit their just-in-case supply chain strategies and shift them to just-in-case models. As a result, warehouses acting as barriers to unexpected circumstances have become more crucial than ever in human history. Apparently, warehousing plays an essential role in any industry but a critical role in health care because of the possible results of any instability and lateness in pharmaceutical deliveries. Different from conventional warehouses, thousands of pharmaceuticals are received, stored, and preserved in pharmaceutical warehouses (pharmahouses) under special storage, handling, temperature, ventilation, and lighting conditions. Moreover, with the increasing older population and chronological or pandemic diseases, thousands of pharmaceuticals are delivered daily to patients, healthcare providers, or pharmacies. Therefore, recent technological advancements are continuously adopted by pharmahouses to cope with the ever-increasing conditions and demand. This chapter presents the history of pharmahouses and their transformation from primitive cellars or storerooms to intelligent facilities. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Warehousing 4.0 in Logistics 4.0
(Springer Nature, 2022) Tutam, M.
Warehousing is an important component of logistics and plays a critical role in contributing to a company’s success. With the advent of e-commerce, warehouses are becoming increasingly more important than ever in logistics. Typically, warehouses receive, store, preserve, retrieve and deliver millions of products on a daily or weekly basis. Therefore, warehouse systems are being continuously revised to accommodate a continuous flow of products in logistics. In recent years, a large and growing number of studies related to the development of warehouses have been conducted. Accordingly, mobile, autonomous, compact, or collaborative systems are increasingly applied in warehouses (called Warehousing 4.0). This chapter presents the state of advancement of Warehousing 4.0 by evaluating the current situation and considers future prospects by including emerging technologies. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.