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Pickup and delivery network segmentation using contiguous geographic clustering / A. I. Jarrah in Journal of the operational research society (JORS), Vol. 62 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 62 N° 10 (Octobre 2011) . - pp. 1827–1843 Titre : Pickup and delivery network segmentation using contiguous geographic clustering Type de document : texte imprimé Auteurs : A. I. Jarrah, Auteur ; J. F. Bard, Auteur Année de publication : 2011 Article en page(s) : pp. 1827–1843 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Clustering  Pickup  and  delivery  operations  Heuristic  column  generation  Aggregation Index. décimale : 001.424 Résumé : This paper addresses the problem of partitioning a local service region into nonoverlapping work areas in which pickups and deliveries are made throughout the day. For a fleet of homogeneous vehicles, a given set of customers, and expected demand for service, the objective is to find the least number of work areas or clusters that satisfy a variety of geometric and capacity constraints. Using rectangles as the basic shape, each cluster must have an aspect ratio that falls within certain bounds, as well as meet load and time requirements dictated by the capacity of a vehicle and the working hours in a day, respectively. The latter requirement presents a unique hurdle because travel times are a function of the actual routes followed by the drivers, and are not known, even in a probabilistic sense, until the clusters are formed. A novel aspect of the paper is the method proposed for dealing with this uncertainty. The problem is modelled using a compact set-covering formulation and is solved with an adaptive column generation heuristic. Because it is not possible to efficiently represent all the constraints in algebraic form, thus allowing a Dantzig-Wolfe decomposition, a constructive approach was taken. The first step involved generating a subset of attractive clusters from seed customers scattered throughout the service region and then iteratively pricing them out to obtain a relaxed solution to the set-covering model. To find integer solutions, a three-phase variable fixing scheme was designed with the aim of balancing solution quality with runtimes. The full methodology was tested on six data sets provided by an internationally known express package carrier. The results showed that vehicle reductions averaging 7.6% could be realized by adopting the configurations derived from the proposed approach. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v62/n10/abs/jors2010123a.html [article] Pickup and delivery network segmentation using contiguous geographic clustering [texte imprimé] / A. I. Jarrah, Auteur ; J. F. Bard, Auteur . - 2011 . - pp. 1827–1843. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 62 N° 10 (Octobre 2011) . - pp. 1827–1843 Mots-clés : Clustering  Pickup  and  delivery  operations  Heuristic  column  generation  Aggregation Index. décimale : 001.424 Résumé : This paper addresses the problem of partitioning a local service region into nonoverlapping work areas in which pickups and deliveries are made throughout the day. For a fleet of homogeneous vehicles, a given set of customers, and expected demand for service, the objective is to find the least number of work areas or clusters that satisfy a variety of geometric and capacity constraints. Using rectangles as the basic shape, each cluster must have an aspect ratio that falls within certain bounds, as well as meet load and time requirements dictated by the capacity of a vehicle and the working hours in a day, respectively. The latter requirement presents a unique hurdle because travel times are a function of the actual routes followed by the drivers, and are not known, even in a probabilistic sense, until the clusters are formed. A novel aspect of the paper is the method proposed for dealing with this uncertainty. The problem is modelled using a compact set-covering formulation and is solved with an adaptive column generation heuristic. Because it is not possible to efficiently represent all the constraints in algebraic form, thus allowing a Dantzig-Wolfe decomposition, a constructive approach was taken. The first step involved generating a subset of attractive clusters from seed customers scattered throughout the service region and then iteratively pricing them out to obtain a relaxed solution to the set-covering model. To find integer solutions, a three-phase variable fixing scheme was designed with the aim of balancing solution quality with runtimes. The full methodology was tested on six data sets provided by an internationally known express package carrier. The results showed that vehicle reductions averaging 7.6% could be realized by adopting the configurations derived from the proposed approach. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v62/n10/abs/jors2010123a.html