Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551014
Pertenecen a esta colección Tesis y Trabajos de grado de los Doctorados correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- The impact of loading-unloading zones for freight vehicles on the last-mile logistics for nanostores in emerging markets(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-11) Mora Quiñones, Camilo Andrés; Cárdenas Barrón, Leopoldo Eduardo; emimmayorquin; Fransoo, Jan C.; Smith Cornejo, Neale Ricardo; Loera Hernández, Imelda de Jesús; School of Engineering and Sciences; Campus Monterrey; Veláaquez Martínez, Josue CuauhtémocEvery year, more than 26 billion deliveries are made globally to serve nanostores, the largest grocery retail channel in the world. At each stop, company representatives face a persistent challenge: finding a place to park. While the problem seems simple, it is remarkably complex and far from easy to solve. In emerging markets, where cities have grown rapidly and often without proper planning, fragmented markets and inadequate infrastructure exacerbate the issue. Multiple stakeholders compete for limited curb space, and the lack of dedicated parking disrupts last-mile efficiency, forcing drivers to either cruise for parking or resort to illegal parking. These behaviors lead to increased vehicle emissions, noise pollution, and additional costs. This dissertation provides key insights into last-mile logistics for nanostores in emerging markets, contributing to academic literature and offering practical implications to address the parking problem. The first study addresses the parking challenges faced by freight vehicles serving nanostores, identifying key factors affecting dwell time efficiency and suggesting operational improvements. In the next study, the focus shifts to the implementation of Loading-Unloading Zones (LUZs) as a targeted intervention, analyzing their impact on reducing air and noise pollution in urban areas. The last study extends this analysis by exploring the effects of LUZs on traffic flow, evidencing how their introduction can improve vehicle speed and reduce congestion in densely populated city streets. Together, these studies provide a detailed exploration of the operational, environmental, and infrastructural challenges of last-mile logistics, while offering concrete strategies to improve urban logistics in emerging markets. This dissertation contributes by expanding the body of knowledge and offering actionable managerial insights with the potential to drive meaningful impact. These include enhancing air quality, reducing noise pollution, lowering carbon emissions, improving traffic flow, and achieving substantial cost savings for companies distributing goods to nanostores in emerging markets.
- Practical inventory models with the warm-up process(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-10) Nobil, Erfan; Cárdenas Barrón, Leopoldo Eduardo; emipsanchez; Loera Hernández, Imelda de Jesús; Treviño Garza,Gerardo; Smith Cornejo, Neale Ricardo; Bourguet Díaz, Rafael Ernesto; School of Engineering and Sciences; Campus MonterreyAs the global population continues to grow, there is an increasing need to enhance the efficiency of production processes. On one hand, manufacturing processes face numerous challenges; on the other hand, various machines in the production line require an initial warm-up phase, which intersects with the fields of operations research and optimization. This dissertation explores the introduction of several concepts along with the warm-up process into the manufacturing workflow. It also addresses a range of issues associated with the warm-up in manufacturing, proposing solutions to these challenges. It tackles common problems in the production line, such as shortages, the environmental impact of carbon emissions, and the production of faulty items. The work at hand employs a diverse set of approaches, from mathematical solutions like the application of the Hessian matrix to the implementation of Karush-Kuhn-Tucker conditions. A variety of methodologies have been applied, ranging from analytical approaches to metaheuristics and innovative deep reinforcement learning techniques. The outcomes of this thesis have resulted in three published papers, with two additional works finished. The publications explore the effect of warm-up process in sustainable EPQ model, the effect of machine downtime on warm-up process, presence of shortage and faulty products with warm-up, machine downtime effect along with shortage on warm-up, and finally multi-product lot scheduling problem with warm-up process. The findings can be regarded as determination of optimal total cost for the system which provides higher revenue for corporations. In case of three published papers, this is done due to analytical approach and mathematical framework, in other words, a closed-form solution represents the whole structure. The solution methodology highlights key concepts, such as shortages and environmental regulations, by comparing results that show how the additional cost of carbon policies and the system’s ability to handle shortages contribute to lower overall costs. In cases involving rework and scrap, rework is shown to incur less cost. Finally, the multi-agent reinforcement learning effectively tackled the stochastic nature of metaheuristic algorithms in fine-tuning the control parameters. Altogether, each paper presents a specific direction within this thesis, and collectively, these provide practical insights for decision-makers in the industry.
- Commercial delivery policies: inventory management models with power demand pattern(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-06-29) Khan, Md. Al-Amin; Cárdenas Barrón, Leopoldo Eduardo; emiggomez, emipsanchez; Loera Hernández, Imelda de Jesús; Smith, Neale R.; Treviño Garza, Gerardo; Bourguet Díaz, Rafael Ernesto; School of Engineering and Sciences; Campus MonterreyIn the fast-paced, ever-changing environment of contemporary business, inventory management stands as a vital, ongoing endeavor. The discipline of decision-making in inventory management assumes a central role in this dynamic environment that is marked by continuous change and intense competition. Navigating the complexities of decision-making poses challenges, particularly in accurately assessing the multifaceted aspects of decision-making processes amid varying circumstances, including demand fluctuations, different types of discounts, and contractual agreements. At the same time, the increasing concern among consumers regarding the environmental footprint of their purchases, coupled with government-mandated regulations, complicates the decision-making process for businesses. In this milieu, sustainable inventory management practices have emerged as a pertinent research area, prompting heightened scrutiny of the impacts of emission guidelines on inventory practices, not only aimed at addressing broader societal concerns but also at ensuring the financial sustainability of businesses. This thesis adopts a specialized demand structure known as the power demand pattern (PDP) to depict fluctuations in demand over the storage period of a company, providing a robust framework for understanding customer demand dynamics across various products. The company maintains its inventory by acquiring items through quantity discounts in exchange for a quantity-sensitive prepayment as part of a contractual arrangement. This thesis introduces a novel concept by considering the installment frequency for fulfilling prepayment obligations as a decision variable for the company, incorporating a transaction fee for each installment. Furthermore, theoretical formulas are developed under different sorts of demand structures, incorporating the influences of selling price and storage time, to assess the profitability of inventory management processes under a combined link-to-order prepayment and quantity discount scheme. A significant advancement by integrating sustainability considerations into both inventory management and pricing strategies within the framework of the PDP is accomplished in this thesis. Through systematic identification and comparison of sustainable inventory management practices under varying emission guidelines, this study provides valuable insights aimed at optimizing profits within the PDP. Therefore, the insights derived from this study offer organizations practical techniques to navigate the complex regulatory environment effectively and achieve sustainable financial performance. Moreover, intensive and comprehensive in-depth sustainable inventory practices under the PDP are established specifically for growing items (GIs). This thesis investigates the impact of weight loss resulting from bleeding and non-consumable components on optimal pricing and inventory strategies for a farm, delving into previously unexplored areas within the literature on GIs. A comparative analysis is conducted on the operations of a livestock farm, operating within several environmental regulations. Consequently, the comprehensive methodology improves sustainable inventory management techniques and offers practical strategies to mitigate environmental impacts and enhance economic feasibility in livestock production.
- Inventory models for growing items in the presence of price-sensitive demandi ncorporating imperfect quality, inspection errors, carbon emissions, and planned backorders(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023-12-13) De la Cruz Márquez, Cynthia Griselle; Cárdenas Barrón, Leopoldo Eduardo; emipsanchez; Loera Hernández, Imelda de Jesús; Bourguet Díaz, Rafael Ernesto; Céspedes Mota, Armando; School of Engineering and Sciences; Campus Monterrey; Smith Cornejo, Neale RicardoRecently, growing items have increasingly come to the forefront within inventory modeling. Unlike conventional items, these items can grow in the cycle of replenishment. They are of paramount importance for human consumption, primarily as a source of high-quality proteins, essential vitamins, and minerals for a balanced diet. Examples of such items include farm animals, plants, and more. Just like any living organism, they require food or nutrients to grow. They are nourished during a growth period and are subsequently sacrificed once they reach a pre-defined target weight, marking the beginning of a timeframe for consumption. The sacrificed products are then stored in inventory and depleted constantly at a specific rate of demand. Throughout the cycle, expenses are incurred for feeding the growing products, while conservation costs are accrued to maintain the sacrificed products in inventory during the consumption period, as well as to sustain the live products for the subsequent cycle. Inventory models have evolved over the years to incorporate features aimed at making them more realistic and robust while addressing specific needs in the field. The concept of imperfect quality is a characteristic assumed to exist in any process due to machine breakdowns and, mong other reasons, inspection errors that are inevitably linked to human error. Inventory shortages do occur in reality, so a company that is prepared for such situations can ensure customer confidence and loyalty. Carbon emissions have gained significance as well. Their reduction is a means of contributing to the fight against climate change and minimizing the environmental impact of corporate operations. Additionally, this reduction can lead to significant cost savings. In short, a reduction in carbon emissions is beneficial both for Mother nature and the long- term success and sustainability of businesses. Another important aspect is models of inventory with price that fluctuates based on demand, which are utilized in specific situations. This occurs when consumers are price-sensitive, and a decrease in price can boost demand. Furthermore, it considers aspects such as item mortality. The relevance of these conditions, combined with the presence of growing items, provides a valuable contribution to the understanding of this relatively new and essential area within inventory theory. In this context, this thesis’ objective is to progressively develop inventory models for growing items incorporating these features. Specifically, 1) to develop an inventory model for growing items with imperfect quality when the demand is price sensitive under carbon emissions and shortages; 2) to generate an inventory model in a three-echelon supply chain for growing items with imperfect quality, mortality, and shortages under carbon emissions when the demand is price sensitive; and 3) to formulate an inventory model for growing items when the demand is price sensitive with imperfect quality, inspection errors, carbon emissions, and planned backorders. The developed inventory models determine the optimal solutions for selling price, backordering quantity, order quantity, and number of shipments to maximize expected total profit per unit of time. Sensitivity analyses and numerical examples are utilized to describe the applicability of the proposed inventory models with the aim of guiding procurement and inventory managers working in industries that store growing items in making informed decisions.