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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

Estimation of liquid-liquid equilibrium for a quaternary system using the GMDH algorithm / Shahbaz Zahr Reyhani in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2129–2134 Titre : Estimation of liquid-liquid equilibrium for a quaternary system using the GMDH algorithm Type de document : texte imprimé Auteurs : Shahbaz Zahr Reyhani, Auteur ; Hossein Ghanadzadeh, Auteur ; Puigjaner, Luis, Auteur Année de publication : 2009 Article en page(s) : p. 2129–2134 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Liquid-liquid  equilibrium  GMDH  technique  Corn  oil  Oleic  acid  Ethanol  Water Résumé : Liquid−liquid equilibrium (LLE) data are important for designing and modeling of process equipment. In this article, the group method of data handling (GMDH) technique has been used to estimate LLE data of the quaternary system of corn oil + oleic acid + ethanol + water at 298.15 K. Using this method, a new model has been proposed that is suitable for use in predicting LLE data. The equilibrium data presented herein were predicted using the GMDH model. To evaluate the performance of the GMDH method, we compared the data predicted using the proposed model with experimental data. Moreover, we compared the deviation between the experimental data and the data estimated with the GMDH. We also used the deviations of some existing models for the comparison. The results show that the proposed model can be used as an efficient tool for estimating LLE data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801082s [article] Estimation of liquid-liquid equilibrium for a quaternary system using the GMDH algorithm [texte imprimé] / Shahbaz Zahr Reyhani, Auteur ; Hossein Ghanadzadeh, Auteur ; Puigjaner, Luis, Auteur . - 2009 . - p. 2129–2134. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2129–2134 Mots-clés : Liquid-liquid  equilibrium  GMDH  technique  Corn  oil  Oleic  acid  Ethanol  Water Résumé : Liquid−liquid equilibrium (LLE) data are important for designing and modeling of process equipment. In this article, the group method of data handling (GMDH) technique has been used to estimate LLE data of the quaternary system of corn oil + oleic acid + ethanol + water at 298.15 K. Using this method, a new model has been proposed that is suitable for use in predicting LLE data. The equilibrium data presented herein were predicted using the GMDH model. To evaluate the performance of the GMDH method, we compared the data predicted using the proposed model with experimental data. Moreover, we compared the deviation between the experimental data and the data estimated with the GMDH. We also used the deviations of some existing models for the comparison. The results show that the proposed model can be used as an efficient tool for estimating LLE data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801082s

Material Transfer Operations in Batch Scheduling / Sergio Ferrer-Nadal in Industrial & engineering chemistry research, Vol. 47 N°20 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7721-7732 Titre : Material Transfer Operations in Batch Scheduling : a critical modeling issue Type de document : texte imprimé Auteurs : Sergio Ferrer-Nadal, Auteur ; Elisabet Capon-Garcia, Auteur ; Carlos A. Méndez, Auteur ; Puigjaner, Luis, Auteur Année de publication : 2008 Article en page(s) : P. 7721-7732 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Batch  Scheduling  mixed-integer  linear  programming  (MILP) Résumé : An effective short-term scheduling formulation must simultaneously deal with several problem difficulties commonly arising in batch processes operations. One of the key features to be considered is the representation of the material transfer operations between process stages. A nonzero time as well as certain conditions and resources are always required to move the material from one processing stage to the next one according to the specified product recipe. The transfer task consumes a period of time during which a proper synchronization of the equipment units supplying and receiving the material is enforced. Synchronization implies that during the execution of the transfer task, one unit will be supplying the material whereas the other one will be receiving it and consequently, no other task can be simultaneously performed in both units. Most of the existing mixed-integer linear programming (MILP) optimization approaches have traditionally dealt with the batch scheduling problem assuming zero transfer times, and consequently no synchronization, between consecutive processing stages. Simplification relying on negligible transfer times may work properly for the scheduling of multiproduct batch plants with similar product recipes; however, it is demonstrated in this work that ignoring the important role of transfer times may seriously compromise the feasibility of the scheduling whenever shared units and storage tanks, material recycles, or bidirectional flows of products are to be considered. To overcome the serious limitations of current MILP-based scheduling approaches, a general precedence-based framework accounting for nonzero transfer times is introduced. Also, two alternative methods that avoid generating unfeasible schedules are proposed and tested in different case studies. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800075u [article] Material Transfer Operations in Batch Scheduling : a critical modeling issue [texte imprimé] / Sergio Ferrer-Nadal, Auteur ; Elisabet Capon-Garcia, Auteur ; Carlos A. Méndez, Auteur ; Puigjaner, Luis, Auteur . - 2008 . - P. 7721-7732. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7721-7732 Mots-clés : Batch  Scheduling  mixed-integer  linear  programming  (MILP) Résumé : An effective short-term scheduling formulation must simultaneously deal with several problem difficulties commonly arising in batch processes operations. One of the key features to be considered is the representation of the material transfer operations between process stages. A nonzero time as well as certain conditions and resources are always required to move the material from one processing stage to the next one according to the specified product recipe. The transfer task consumes a period of time during which a proper synchronization of the equipment units supplying and receiving the material is enforced. Synchronization implies that during the execution of the transfer task, one unit will be supplying the material whereas the other one will be receiving it and consequently, no other task can be simultaneously performed in both units. Most of the existing mixed-integer linear programming (MILP) optimization approaches have traditionally dealt with the batch scheduling problem assuming zero transfer times, and consequently no synchronization, between consecutive processing stages. Simplification relying on negligible transfer times may work properly for the scheduling of multiproduct batch plants with similar product recipes; however, it is demonstrated in this work that ignoring the important role of transfer times may seriously compromise the feasibility of the scheduling whenever shared units and storage tanks, material recycles, or bidirectional flows of products are to be considered. To overcome the serious limitations of current MILP-based scheduling approaches, a general precedence-based framework accounting for nonzero transfer times is introduced. Also, two alternative methods that avoid generating unfeasible schedules are proposed and tested in different case studies. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800075u

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) 

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Tracking the dynamics of the supply chain for enhanced production sustainability / Puigjaner, Luis in Industrial & engineering chemistry research, Vol. 48 N° 21 (Novembre 2009) 

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