The one container drayage problem with soft time windows

Intermodal freight transport consists of using different modes of transport without changing the load unit. This results in a significant reduction in the time that goods spend at intermodal terminals, where transshipment takes place. Drayage refers to the transport of freight on trucks among intermodal terminals, depots, customers and suppliers. In spite of the fact that drayage only represents between 5 and 10 percent of total distance, it may amount up to more than 30 percent of the total costs. The aim of this work is to study drayage operations. First, an extensive literature review is undertaken. Since the intermodal transport chain can become more efficient by means of a proper organisation of the drayage movements, the optimization of the daily drayage problem has been identified as one of the main ways of reducing the drayage cost and improving intermodal operations. On this problem, the lack of a common benchmark has hindered reaching further conclusions from all the research carried out. Therefore, this paper proposes a common framework and presents a generalized formulation of the problem, which allows modeling most drayage policies, with the limitation of only considering one-container problems. Results show that flexible tasks in the repositioning of empty containers as well as soft time windows can reduce the operating costs and facilitate the management of drayage companies. This work may help consider adequate policies regarding drayage operations in intermodal terminals

Optimización del despacho de llamadas mediante la inclusión de la consideración del tiempo de espera relativo

[ESP] La incesante revalorización del suelo urbano y la necesidad de maximizar el aprovechamiento de éste tienen como consecuencia la construcción de rascacielos y edificios de altura cada vez mayor. En estas instalaciones el transporte vertical constituye un verdadero problema logístico. Se define éste como el desplazamiento en sentido ascendente y descendente de personas y bienes a través de las plantas de un edifico. Los medios disponibles para llevar a cabo dicho transporte son dos y complementarios: escaleras y ascensores. Ambos parámetros no son totalmente independientes el uno del otro sino que existe un cierto grado de correlación entre ambos de forma que una vez alcanzado un diseño óptimo es difícil mejorar uno sin empeorar el otro

Aplicación de la regresión logística para la predicción de roturas de tuberías en redes de abastecimiento de agua

Las roturas de tuberías en redes de abastecimiento de agua provocan serios problemas para las compañías encargadas de su gestión. Con objeto de reducir el número de roturas inesperadas, se propone un método predictivo de clasificación de las tuberías que utiliza la regresión logística, junto con técnicas avanzadas de procesamiento de datos, como el equilibrado de clases o la validación cruzada. La metodología se ha aplicado al caso real de la red de abastecimiento de Sevilla. Los resultados muestran que podría llegar a predecirse el 85.9% de las roturas de tuberías, siendo 76.6% la precisión total del modelo.Universidad de Sevilla (España) VI PPIT-U

Optimal design of water supply networks using a tabu search algorithm

International Conference on Industrial Engineering and Industrial Management (13th. 2019. Gijón

Predicción de rotura de tuberías en redes de abastecimiento de agua a través de un modelo de regresión logística

International Conference on Industrial Engineering and Industrial Management (13th. 2019. Gijón

Solving the order batching and sequencing problem with multiple pickers: a grouped genetic algorithm

International Conference on Industrial Engineering and Industrial Management (13th. 2019. Gijón

Distribución de mercancías y desarrollo urbano sostenible

Urban freight deliveries should be analyzed by focusing on the three sustainability axes: economic, social and environmental. Within the scope of sustainable urban development, it is important to develop an urban freight system that is sustainable and efficient, which is extremely complex due to the enormous variety of freight deliveries co-existing in a city and to the multiple stakeholder groups involved in the problem, which often results in the appearance of conflict areas. This paper describes all that complexity and provides details on the main responses that may be given at the urban framework, both from the industry and from the local authority, always taking into account that the regulations imposed to achieve sustainability in urban freight deliveries might not result as expected.El reparto urbano de mercancías debe ser contemplado en relación con los tres ejes de la sostenibilidad: el económico, el social y el medioambiental. Dentro de los parámetros del desarrollo urbano sostenible, es importante conseguir una logística urbana sostenible y eficiente, lo cual es extremadamente complejo debido a la gran variedad de repartos de mercancía existentes en la ciudad y a los numerosos grupos de actores involucrados en el problema, lo cual genera con frecuencia numerosas áreas de conflicto. En este artículo se describe toda esa complejidad y se detallan las principales respuestas que pueden darse en el ámbito urbano, tanto a nivel empresarial como desde la administración local, teniendo en cuenta el riesgo de que en ocasiones el resultado de las medidas impuestas para conseguir un reparto de mercancías más sostenibles no sea el esperado.

Flexible Job Shop Scheduling Problem with Fuzzy Times and Due-Windows: Minimizing Weighted Tardiness and Earliness Using Genetic Algorithms

The current requirements of many manufacturing companies, such as the fashion, textile, and clothing industries, involve the production of multiple products with different processing routes and products with short life cycles, which prevents obtaining deterministic setup and processing times. Likewise, several industries present restrictions when changing from one reference to another in the production system, incurring variable and sequence-dependent setup times. Therefore, this article aims to solve the flexible job shop scheduling problem (FJSSP) considering due windows, sequence-dependent setup times, and uncertainty in processing and setup times. A genetic algorithm is proposed to solve the FJSSP by integrating fuzzy logic to minimize the weighted penalties for tardiness/earliness. The proposed algorithm is implemented in a real-world case study of a fabric finishing production system, and it is compared with four heuristics adapted to the FJSSP such as earliest due date, critical reason, shortest processing time, and Monte Carlo simulation. Results show that the performance of the proposed algorithm provides efficient and satisfactory solutions concerning the objective function and computing time since it overperforms (more than 30%) the heuristics used as benchmarks