Sawadogo M.,University of Lorraine |
Anciaux D.,University of Lorraine |
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2012
There is no doubt that the transport sector contributes significantly to the overall energy consumption and emission of greenhouse gases. The transportation systems are increasingly related to environmental problems. The present contribution aims to take into account the direct and indirect impacts of transportation systems whatsoever on the environment or on the society. This paper proposes the reduction of environmental and societal impacts of intermodal freight by using multiobjective shortest path approach. A novel algorithm called Multiobjective Ant colony Algorithm for Multiobjective Shortest Path Problem (MOSPACO) is presented. This algorithm aims to help decision makers to choose a path with less environmental impacts in an intermodal network. The ant colony optimization metaheuristic is used to choose the 'best' path in the network, which means the path with the best compromise economy/environment. A numerical analysis is then presented based on a network build using real geographical data and the obtained non-dominated solutions are analyzed. © 2012 IFAC.
Radhoui M.,Cerep |
Rezg N.,LGIPM |
Journal of Intelligent Manufacturing | Year: 2010
In this paper, we develop a joint quality control and preventive maintenance policy for a production system producing conforming and nonconforming units. The considered system consists of one machine which must supply another production line operating on a just-in-time basis. Each lot produced by the machine is subject to a quality control. According to the proportion l of nonconforming units observed and compared to a threshold value l m, one decides to undertake or not maintenance actions on the system. In order to palliate perturbations caused by the stopping of the machine for preventive and corrective maintenance actions of random durations, a buffer stock h is built up to ensure the continuous supply of the subsequent production line. The proposed strategy is modelled using simulation and experimental design. This approach allows to generate a second order response surface allowing to easily determine the optimal rate, l m*, of nonconforming units on the basis of which preventive maintenance actions should be performed, and the optimal size, h*, of the buffer stock to be built. These values minimize the total cost per time unit which includes the costs related to maintenance, quality and inventory. © 2008 Springer Science+Business Media, LLC.
Dahane M.,LGIPM |
Dahane M.,Metz National School of Engineering |
Dellagi S.,LGIPM |
Dellagi S.,Metz National School of Engineering |
And 4 more authors.
International Journal of Production Research | Year: 2011
This article, inspired by an industrial problem, develops efficient maintenance and just-in-time production policies in a subcontracting environment according to two orientations. The first invokes subcontracting with the objective of satisfying a constant customer demand knowing that our production system, composed of a machine M 1, cannot satisfy the totality of demand. Subcontracting is represented by a machine M 2 which has a constant failure rate, while three maintenance policies for M 1 are tested and evaluated. The second orientation takes the perspective of our production system as a supplier which is obliged to allocate part of its production capacity to subcontracting so as to satisfy a constant demand. We consider a production system made up of two machines, both of which produce a single type of product, are subject to breakdowns and can carry out subcontracting tasks. The objective of this part of the article is to prove the efficiency of the so-called integrated maintenance policy, which combines production and maintenance decisions in a subcontracting environment. © 2011 Taylor & Francis.