Models, algorithms, and heuristics for multiobjective commercial territory design

In general, distribution firms have complex product distribution networks which are formed by thousands of sales points. In this kind of industry there are many interesting problems from the logistic point of view that can appear in different stages of the decision process. For instance, when a firm is starting, a first problem could be the facility location: where to install the warehouses and/or distribution centers. After that, in order to provide efficient service and to reduce total costs (i.e., production, stock and distribution costs) some questions such as how many products need to be produced, and how to deliver the products to the final customer, need to be answered

Embotelladoras ARCA Uses Operations Research to Improve Territory Design Plans

Embotelladoras ARCA was formed in 2001 by integrating three of the oldest bottlers in Mexico and became the second largest bottler of Coca-Cola products in Latin America. The company distributes its products in the northern region of Mexico and, since 2008, in the north of Argentina and Ecuador. The company have soft-drink sales of more than 1.2 billion unit cases and ranks as the third-largest Coca-Cola bottler in the world. The large size of the market and the relevance of a number of problems faced by the company motivate the use and application of operations research models and techniques One of the most relevant problems the company faces is that of how to segment or partition their customers into clusters or territories to accomodate for a better handling of marketing and distribution decisions. This territory design is not entirely arbitrary since it must satisfy several planning requirements such as territory compactness, territory connectivity, territory balancing, and similarity with existing design. Before 2009, these units were defined by “experience” without quantitative tools giving more weight to the territory compactness criterion. This led to a number of undesirable issues such as highly unbalanced territories, that is, the plans ended up with a large disparity in size with respect to both number of customers and total product sales. This imbalance had a negative effect among company workers since each territory (customer order capturing by sales associates, product routing by truck drivers, and so on) is handled by a different team. In this paper, we apply operations research methods to determine better configurations of the territorial units to ensure that each formed territory is relatively similar in size with respect to both number of customers and total product sales while ensuring some other important planning requirements and maximizing territory compactness. The usage of this methodology has resulted in many important benefits for the company, in particular, it has had a significant improvement with respect to the territory imbalances improving from 30 to 5 %. We highlight some other side benefits resulting from this approach. The company has adopted this proposed tool to make their territory design decisions

Zone design of specific sizes using adaptive additively weighted voronoi diagrams

Territory or zone design processes entail partitioning a geographic space, organized as a set of areal units, into different regions or zones according to a specific set of criteria that are dependent on the application context. In most cases, the aim is to create zones of approximately equal sizes (zones with equal numbers of inhabitants, same average sales, etc.). However, some of the new applications that have emerged, particularly in the context of sustainable development policies, are aimed at defining zones of a predetermined, though not necessarily similar, size. In addition, the zones should be built around a given set of seeds. This type of partitioning has not been sufficiently researched; therefore, there are no known approaches for automated zone delimitation. This study proposes a new method based on a discrete version of the adaptive additively weighted Voronoi diagram that makes it possible to partition a two-dimensional space into zones of specific sizes, taking both the position and the weight of each seed into account. The method consists of repeatedly solving a traditional additively weighted Voronoi diagram, so that each seed?s weight is updated at every iteration. The zones are geographically connected using a metric based on the shortest path. Tests conducted on the extensive farming system of three municipalities in Castile-La Mancha (Spain) have established that the proposed heuristic procedure is valid for solving this type of partitioning problem. Nevertheless, these tests confirmed that the given seed position determines the spatial configuration the method must solve and this may have a great impact on the resulting partition

The political economy of Hong Kong's "open skies" legal regime: an empirical and theoretical exploration

Copyright 2009 San Diego International Law Journal. Reprinted with the permission of the San Diego International Law Journal.The article presents an empirical and theoretical research which describes the functions of the international legal regime through powerful economic forces in Hong Kong, China. The government applied aviation policies with respect to open skies platform to provide a basis for a thorough understanding of government's legitimacy based on neoclassical logic and analysis. Conceptual perspectives of realists, liberals and cognitivists were acknowledged by the economically-inspired nationalists

Microgrids:experiences, barriers and success factors

Although microgrids have been researched for over a decade and recognized for their multitude of benefits to improve power reliability, security, sustainability, and decrease power costs for the consumer, they have still not reached rapid commercial growth. The main aim of this research is to identify the common barriers and ultimate success factors to implementing a microgrid in the real world. We found that microgrids vary significantly depending on location, components, and optimization goals, which cause them to experience different types of challenges and barriers. However, the most common barriers were identified and grouped into four categories: technical, regulatory, financial, and stakeholder, based on the literature and overlying patterns recognized amongst the thirteen case studies. The most common technical barriers include problems with technology components, dual-mode switching from grid-connected to island mode, power quality and control, and protection issues. There is extensive research on how to overcome these issues, so technical solutions are becoming available yet case specific. Regulatory barriers exist due to interconnection rules with the main grid and the prohibition of bi-directional power flow and local power trading between microgrid and the main network. The latter issue is the barrier experienced most often and has only recently been addressed, so solutions need further research. The main financial barrier is still the burden of high investment and replacement costs of the microgrid. This can be resolved with proper market support in the short term and might naturally resolve itself through learning over the long run. Lastly, stakeholder barriers include issues with conflicting self-interest and trust, and having the expertise to manage operations. These stakeholder barriers are not yet addressed in the literature and need to be further researched

Estado del arte en procesos de zonificacion

Los procesos de partición espacial implican la división de un espacio geográfico en diferentes unidades o zonas según un conjunto específico de criterios. En ámbitos relacionados con las ciencias geoespaciales, la delimitación de estas zonas se realiza por agrupación de otras unidades básicas de área existentes en el espacio de trabajo. En este artículo se ofrece una revisión de los métodos de solución diseñados para este tipo de problemas, comenzando por una introducción a las técnicas heurísticas y modelos matemáticos más utilizados desde los años 60, para finalizar describiendo los recientes algoritmos aplicados a diagramas de Voronoi. También se revisan las aplicaciones en las que se han implementado algunos de estos modelos, quedando patente que son herramientas diseñadas para el tratamiento de problemas específicos, dada la dificultad de diseñar modelos genéricos y versátiles para este tipo de particiones espaciales o zonificacione