Co-distribución para logística urbana: análisis de experiencias internacionales

Population growth has been accompanied by an increase in the percentage of people living in urban centers in both developed and non-developed countries. These areas with high population density generate an increase in commercial activity, with urban freight transport being a key factor, as it provides the products marketed by its stores. However, market capillarity, strict time windows and lack of infrastructure cause this activity to be carried out inefficiently and therefore, at a high cost. Moreover, urban freight transportation affects other externalities such as contamination, noise and existing traffic congestion. Several authors have proposed co-distribution as a way to improve the distribution system and mitigate the problems mentioned above. This article aims to gather and analyze information on the different methods used in co-distribution in different parts of the world, supported by practical experiences. As a result, it is concluded that almost all articles published in this subject refer to the implementation of Urban Consolidation Centers, which, while mitigating several of the problems mentioned, they generally need support from the government to make them economically viable.El crecimiento en la población ha sido acompañado por un aumento en el porcentaje de las personas que habitan los centros urbanos, tanto en países desarrollados como no desarrollados. Estas zonas con alta densidad de población generan un aumento en la actividad comercial, siendo el transporte urbano de mercaderías un factor clave, ya que provee los productos comercializados por sus tiendas. Sin embargo, la capilaridad del mercado, estrictas ventanas horarias y falta de infraestructura provocan que esta actividad se realice de manera ineficiente y por lo tanto, a un costo elevado. Por otro lado, el transporte de mercaderías afecta otras externalidades como la contaminación, el ruido y la congestión de tránsito ya existente. Varios autores han investigado la co-distribución como una forma de mejorar el sistema de distribución urbana y mitigar los problemas anteriormente mencionados. Este artículo pretende recopilar y analizar la información sobre los diferentes métodos utilizados en co-distribución a nivel mundial con sustento en experiencias prácticas. Como resultado, se concluye que casi la totalidad de los artículos publicados en esta temática refieren a la implementación de Centros de Consolidación Urbanos (CCU), los cuales, si bien mitigan varios de los problemas mencionados, en general necesitan de apoyo por parte del gobierno para que sean económicamente viables

Optimal Fulfillment Strategies in an Omnichannel Retail Supply Chain

With the development of digital technologies, more and more brick-and-mortar stores are starting to offer the online channel to sell their products. For example, Walmart and Whole Foods are selling fresh groceries from both their websites and store locations. As a result, such omnichannel retailers need to serve both online and in-store demand. To do that, the retailer may choose to fulfill online demand from a centralized distribution center (DC), or by utilizing inventory of stores. In this thesis, I explore the optimal fulfillment strategies of an omni-channel retailer. Firstly, consider customers’ behavior when they face online and in-store purchase options. Using utility theory, model customers’ behavior in preferring either channel. Secondly, I explore the impacts of retailers’ fulfillment choices on its inventory cost, shipping and delivery cost, as well as overall profitability. This thesis identifies conditions under which either fulfillment strategy (i.e., from DC or stores) is optimal. And find that the optimal fulfillment strategy is dependent on the total number of stores, unit inventory cost at the stores and DC, unit delivery cost, product prices and number of stores. Case studies based on Manhattan and Los Angeles are provided to further investigate the retailer's fulfillment decision as well as the impacts of its pricing decision, and geographic and cost characteristics. For Manhattan, for both exogenous and endogenous price cases, the regions where store fulfillment are optimal first decrease and then increases as the total number of stores increases. For Los Angeles, the region where store fulfillment is optimal always increases with the total number of stores.Master of Science in EngineeringIndustrial and Systems Engineering, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttps://deepblue.lib.umich.edu/bitstream/2027.42/154712/1/Wenqing Shi Final Thesis.pdfDescription of Wenqing Shi Final Thesis.pdf : Thesi

Last mile delivery in the retail sector in an urban context

Last mile delivery (LMD) is a critical yet ambiguous stage of every supply chain. Previous studies have indicated that LMD is one of the most expensive, inefficient and polluting stages of the supply chain yet, despite its importance, the concept of LMD remains unclear in both academic and industry contexts. The use of different phrases, unclear boundaries and uncertain definitions and structures cause LMD to remain unclear. Thus, this study aims to demystify the basic understanding of LMD in terms of terminology, definition, scope, dimensions and structures. It then aims to introduce an initiative to improve the performance of LMD. A systematic literature review and content analysis are used to clarify the definition, dominant terminology and boundary of LMD, and investigate how the literature addresses these. The study then uses the ontology concept to discover and classify the LMD component, which provides a framework for extracting potential problems, solutions and structures for LMD. The proposed ontology is also used to map the LMD literature and identify the gaps in the literature. Using the proposed ontology, LMD is categorised into 40 structures that are employed to discover the structure of LMD used by major retailers and third-party logistics in the city of Melbourne. The results indicate that warehouses and distribution centres are the most common places that the investigated companies used to begin LMD. The results also indicate that the LMD process is usually finalised at stores in the business-to-business (B2B) context, while it is finalised at consignees location in the business-to-consumer (B2C) context. The companies investigated in this study mostly prepared the orders at factories, warehouses or distribution centres in the B2B context and prepared orders at stores in the B2C context. Considering these findings, along with coopetition strategy, this study develops an initiative to improve LMD performance. This study proposes a conceptual model for collaboration in the form of coopetition between retailers and logistics providers, and develops mathematical models to evaluate and optimise the initiative. The conceptual model is formed based on sharing 'empty running vehicles' between different delivery networks to decrease the cost and lead-time of delivery simultaneously. A mixed-integer linear programming model solved by genetic algorithm is developed to discover the optimised vehicle-sharing combinations. The results indicate that the proposed model with coopetition decreases delivery cost and lead-time by 60% and 56%, respectively. The results also indicate that the model reduces travelling distance by 66%, which contributes positively to environmental effects. The scenarios with and without coopetition strategy are then compared using real data from the city of Melbourne, which confirms the improvements of the proposed model with coopetition. The results of a case study show that the LMD model with coopetition strategy reduces cost, lead-time and travelling distance by 55%, 46% and 64%, respectively, which is almost similar to the results of random instance sets. This thesis makes significant theoretical and practical contributions in relation to LMD and employing coopetition strategy in this area. This thesis provides a conclusion regarding the domain terminology, definition and scope of LMD, and presents classified components and structures of LMD, which help create a common understanding among people working and studying in this field. This study presents an LMD model with coopetition among carriers sharing empty running vehicles, which decreases cost, lead-time, travelling distance and the number of vehicles required. The implementation of the proposed model on a large scale can reduce congestion and improve the sustainability aspects of deliveries in cities. The results of this study encourage decision makers in government authorities to identify empty running vehicles in cities and facilitate collaboration among different networks and companies. Moreover, LMD stakeholders such as residents, authorities and end consumers may enjoy the benefits of the proposed coopetition model without being involved in the coopetition practice directly. A shorter time for receiving parcels and lower price of service are the potential benefits experienced by end consumers, while reduced traffic and reduced negative environmental effects are the potential advantages for residents and government authorities. An initiative two-echelon vehicle routing problem (VRP) model is presented to simultaneously minimise lead-time and cost in this study, which has not previously been presented in the LMD context. Moreover, the proposed two-echelon VRP model can be used in other contexts and disciplines