Julian Andres Zapata Cortes

Modeling The Inventory Routing Problem (IRP) With Multiple Depots With Genetic Algorithms

This paper presents the application of Inventory Routing Problem (IRP) for the distribution of goods between multiple clients (n) and multiple suppliers (m), which is based on the concept of collaboration between companies through vendor managed inventory (VMI). A review of the processes of distribution and routing of goods including the variable inventory and the IRP model with multiple warehouses are presented and it is proposed a genetic algorithm for its solution. The distribution of goods is a key process in the supply chain, since it plays a decisive role in the business logistics costs and in service level provided to customers. The current competitive environment has led companies to work together through partnerships of cooperation and collaboration processes, leading to find new forms of distribution involving multiple suppliers and multiple customers. The main results of the model and the proposed genetic algorithm, reductions in inventory costs and transportation to the problem studied are obtained. Keywords— Inventory Routing Problem, Genetic Algorithms, Costs of transport, Costs of inventory, Distribution of Goods.

Multiobjective Model For The Simultaneous Optimization Of Transportation Costs, Inventory Costs And Service Level In Goods Distribution

This paper presents a model formulation for the multiobjetive optimization of transportation costs, inventory costs and service level for the goods distribution process. The multiobjective model is composed by two objective functions, in which the transportation and inventory cost are optimized using the Inventory Routing Problem (IRP) and the service level is optimized using the number of accomplished time windows for the vehicles in the routing process. The model is solved using the Nondominated Sorting Genetic Algorithm II (NSGAII), implementing a novel representation of the chromosome, which allows assigning inventory and routes simultaneously. The algorithm allows calculating the Pareto Frontier for the analyzed distribution case, observing good qualities in the solution, compared with what is found in scientific literature.

Indicadores de desempeño para empresas del sector logístico: Un enfoque desde el transporte de carga terrestre

espanolEl presente articulo propone un nuevo marco metodologico para el desarrollo de indicadores que permitan medir el desempeno de las actividades clave para cuatro areas decisionales identificadas en las empresas de transporte de carga terrestre, siendo estas: gerencia, soporte administrativo, operaciones -logistica- y tecnologia de procesos. La propuesta teorica se basa en un analisis detallado de literatura cientifica, de este analisis es posible identificar las actividades clave en cada area decisional de las empresas, al igual que los recursos que se ven afectados por variables internas o externas a la operacion y que impactan el desempeno empresarial. Como resultado se propone un marco de indicadores para la medicion del desempeno de las empresas de transporte de carga que incluye la definicion de cada indicador y como calcularlo. Finalmente, se concluye que es posible obtener un conjunto de indicadores que se basen en las necesidades identificadas en literatura cientifica sin obviar las particularidades de las empresas de transporte de carga, lo que asegura la funcionalidad y el exito de la implementacion de estos indicadores. EnglishThis paper proposes a new methodological framework for the indicators development that allows measuringe the performance of the key activities on the four decisional areas identified on the land freight transport companies: Management, Administrative support, Operations - Logistics and Process technology. The theoretical proposal is based on a detailed analysis of scientific literature, with this analysis is possible to identify the key activities in each decisional area and the resources that are affected by internal or external variables and impact business performance. As a result, a framework of indicators for measuring the performance of freight companies is proposed, including the definition of each indicator and how to calculate it. Finally, it is concluded that it is possible to obtain a set of signs based on needs identified in scientific literature without forgetting the peculiarities of freight transport companies, which ensures functionality and successful implementation of these indicators.

Metaheuristics for multiobjective goods routing

Good transportation is a key activity within the supply chain, as it has a direct impact on the companys total costs and in customers service, giving it a special interest for seeking ways to optimize these distribution processes. In the literature there is a large number of approaches to optimize these processes, which generally require advanced methods for its solution. This article reviews the most used metaheuristics for solving multiobjective problems applied in goods distribution networks and analyzes the most common objectives used in such approaches. Some trends are identified in order to suggest some areas for future research.