Documents disponibles écrits par cet auteur

An efficient mixed-integer linear programming scheduling framework for addressing sequence-dependent setup issues in batch plants / Kopanos, Georgios M. in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6346–6357 Titre : An efficient mixed-integer linear programming scheduling framework for addressing sequence-dependent setup issues in batch plants Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; José Miguel Lainez, Auteur ; Puigjaner, Luis, Auteur Année de publication : 2009 Article en page(s) : pp. 6346–6357 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Mixed-integer  linear  programming  scheduling  framework  Sequence-dependent  setup  times Résumé : Setup times and/or costs appear in a plethora of industrial and service applications. Sequence-dependent setup times and costs entail significantly complex scheduling problems. In this paper, a new continuous time precedence-based mixed-integer linear programming scheduling framework is developed for dealing with sequence-dependent setup time and/or cost issues. This model is based on the unit-specific general precedence concept, which is introduced in this paper. Several case studies are carried out in order to highlight the efficiency and the special features of the proposed model. Comparisons were made with the existing precedence-based formulations. Medium-sized scheduling problems can be solved by the proposed framework with relatively low computational effort. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801127t [article] An efficient mixed-integer linear programming scheduling framework for addressing sequence-dependent setup issues in batch plants [texte imprimé] / Kopanos, Georgios M., Auteur ; José Miguel Lainez, Auteur ; Puigjaner, Luis, Auteur . - 2009 . - pp. 6346–6357. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6346–6357 Mots-clés : Mixed-integer  linear  programming  scheduling  framework  Sequence-dependent  setup  times Résumé : Setup times and/or costs appear in a plethora of industrial and service applications. Sequence-dependent setup times and costs entail significantly complex scheduling problems. In this paper, a new continuous time precedence-based mixed-integer linear programming scheduling framework is developed for dealing with sequence-dependent setup time and/or cost issues. This model is based on the unit-specific general precedence concept, which is introduced in this paper. Several case studies are carried out in order to highlight the efficiency and the special features of the proposed model. Comparisons were made with the existing precedence-based formulations. Medium-sized scheduling problems can be solved by the proposed framework with relatively low computational effort. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801127t

Costs for rescheduling actions / Kopanos, Georgios M. ; Elisabet Capon-Garcia ; Antonio Espuna ; Puigjaner, Luis in Industrial & engineering chemistry research, Vol. 47 n°22 (Novembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8785–8795 Titre : Costs for rescheduling actions : a critical issue for reducing the gap between scheduling theory and practice Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; Elisabet Capon-Garcia, Auteur ; Antonio Espuna, Auteur ; Puigjaner, Luis, Auteur Année de publication : 2008 Article en page(s) : p. 8785–8795 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Scheduling Résumé : Rescheduling programmed tasks, when an unexpected event occurs, may affect the smooth operation of the plant if the initial schedule is not taken into account. This work addresses the penalty incurred by rescheduling actions and the optimization procedure to preserve schedule stability. To adjust the rescheduling process to the needs of the decision-maker, rescheduling costs are included to the initial objective function. Namely, unit reallocation and sequencing alterations are the sources of rescheduling costs. A mixed-integer linear programming (MILP) model for the simultaneous rescheduling of multiple operations that permits local reordering, unit reallocation, and accommodation of new orders, is considered. The need to consider rescheduling penalties in the optimization procedure is highlighted through several case studies. As a result, the production plant stability and efficiency are preserved, whereas the generation of pseudo-optimal schedules is avoided. In addition, the tradeoff between the original objective function optimization and the smooth operation of the plant is thoroughly examined. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005676 [article] Costs for rescheduling actions : a critical issue for reducing the gap between scheduling theory and practice [texte imprimé] / Kopanos, Georgios M., Auteur ; Elisabet Capon-Garcia, Auteur ; Antonio Espuna, Auteur ; Puigjaner, Luis, Auteur . - 2008 . - p. 8785–8795. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8785–8795 Mots-clés : Scheduling Résumé : Rescheduling programmed tasks, when an unexpected event occurs, may affect the smooth operation of the plant if the initial schedule is not taken into account. This work addresses the penalty incurred by rescheduling actions and the optimization procedure to preserve schedule stability. To adjust the rescheduling process to the needs of the decision-maker, rescheduling costs are included to the initial objective function. Namely, unit reallocation and sequencing alterations are the sources of rescheduling costs. A mixed-integer linear programming (MILP) model for the simultaneous rescheduling of multiple operations that permits local reordering, unit reallocation, and accommodation of new orders, is considered. The need to consider rescheduling penalties in the optimization procedure is highlighted through several case studies. As a result, the production plant stability and efficiency are preserved, whereas the generation of pseudo-optimal schedules is avoided. In addition, the tradeoff between the original objective function optimization and the smooth operation of the plant is thoroughly examined. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005676

Optimal production scheduling and lot-sizing in dairy plants / Kopanos, Georgios M. in Industrial & engineering chemistry research, Vol. 49 N° 2 (Janvier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 701–718 Titre : Optimal production scheduling and lot-sizing in dairy plants : the yogurt production line Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Georgiadis, Michael C., Auteur Année de publication : 2010 Article en page(s) : pp 701–718 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Yogurt  production  Pasteurization  Homogenization. Résumé : The lot-sizing and production scheduling problem in a multiproduct yogurt production line of a real-life dairy plant is addressed in this work. A new mixed discrete/continuous-time mixed-integer linear programming model, based on the definition of families of products, is proposed. The problem under question is mainly focused on the packaging stage, whereas timing and capacity constraints are imposed with respect to the pasteurization/homogenization and fermentation stage. Packaging units operate in parallel and share common resources. Sequence-dependent times and costs are explicitly taken into account and optimized by the proposed framework. Several scenarios for a large-scale dairy plant have been solved to optimality using the proposed model. Production bottlenecks are revealed, and several retrofit design options are proposed to enhance the production capacity and flexibility of the plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901013k [article] Optimal production scheduling and lot-sizing in dairy plants : the yogurt production line [texte imprimé] / Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Georgiadis, Michael C., Auteur . - 2010 . - pp 701–718. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 701–718 Mots-clés : Yogurt  production  Pasteurization  Homogenization. Résumé : The lot-sizing and production scheduling problem in a multiproduct yogurt production line of a real-life dairy plant is addressed in this work. A new mixed discrete/continuous-time mixed-integer linear programming model, based on the definition of families of products, is proposed. The problem under question is mainly focused on the packaging stage, whereas timing and capacity constraints are imposed with respect to the pasteurization/homogenization and fermentation stage. Packaging units operate in parallel and share common resources. Sequence-dependent times and costs are explicitly taken into account and optimized by the proposed framework. Several scenarios for a large-scale dairy plant have been solved to optimality using the proposed model. Production bottlenecks are revealed, and several retrofit design options are proposed to enhance the production capacity and flexibility of the plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901013k

Production scheduling in multiproduct multistage semicontinuous food processes / Kopanos, Georgios M. in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6316-6324 Titre : Production scheduling in multiproduct multistage semicontinuous food processes Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Michael C. Georgiadis, Auteur Année de publication : 2011 Article en page(s) : pp. 6316-6324 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Food  engineering  Semicontinuous  Scheduling  Production Résumé : This works presents a novel mixed-integer programming framework and a solution strategy for the optimal production scheduling of multiproduct and multistage food process industries, such as ice-cream production facilities, studied in detail. The overall mathematical framework relies on an efficient modeling approach of the sequencing decisions, the integrated modeling of all production stages, and the inclusion of strong valid integer cuts in the formulation. The simultaneous optimization of all processing stages increases the plant production capacity, reduces the production cost for final products, and facilitates interaction among the different departments of the production facility. Several instances of a real-life industrial case study concerning ice-cream production have been solved to optimality to illustrate the applicability and efficiency of the overall modeling and solution approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158926 [article] Production scheduling in multiproduct multistage semicontinuous food processes [texte imprimé] / Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Michael C. Georgiadis, Auteur . - 2011 . - pp. 6316-6324. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6316-6324 Mots-clés : Food  engineering  Semicontinuous  Scheduling  Production Résumé : This works presents a novel mixed-integer programming framework and a solution strategy for the optimal production scheduling of multiproduct and multistage food process industries, such as ice-cream production facilities, studied in detail. The overall mathematical framework relies on an efficient modeling approach of the sequencing decisions, the integrated modeling of all production stages, and the inclusion of strong valid integer cuts in the formulation. The simultaneous optimization of all processing stages increases the plant production capacity, reduces the production cost for final products, and facilitates interaction among the different departments of the production facility. Several instances of a real-life industrial case study concerning ice-cream production have been solved to optimality to illustrate the applicability and efficiency of the overall modeling and solution approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158926