Optimización multi-objetivo para la programación de la producción

El problema del taller de flujo surge hace unos 60 años como una aproximación de la realidad de los procesos industriales de fabricación, más exactamente de la programación de la producción. La programación de la producción se refiere a la ordenación de las tareas productivas pendientes en una industria fabril. A pesar de que han pasado muchos años desde sus comienzos, aun hoy existe una gran diferencia entre los problemas teóricos propuestos y la realidad industrial de las empresas. Una de las diferencias más evidentes es el hecho de que al intentar resolver un problema de programación de la producción casi nunca se tiene en mente un único objetivo. Normalmente se tienen en mente varias cosas a la vez, como por ejemplo, terminar cuanto antes la producción, al mismo tiempo maximizar el uso de recursos y también cumplir con las fechas de entregas. En este contexto han surgido los problemas de taller de flujo multi-objetivo. En los últimos 20 años los problemas de taller de flujo multi-objetivo han tenido un gran empuje, acercado el desarrollo teórico a los problemas reales. En este trabajo de tesis presentaremos un recorrido por algunos de los problemas de taller de flujo multi-objetivo, partiendo desde los más básicos y yendo hacia los más complejos, y al mismo tiempo, los que reflejan mejor la realidad. Este trabajo tiene además otros objetivos. Uno de los problemas que más se ha dejado de lado en la optimización multi-objetivo es la medición y comparación correcta de los resultados. Presentaremos un recorrido por los métodos existentes para la medición de resultados multi-objetivo, señalando los problemas y ventajas de cada uno, con la finalidad de obtener una metodología válida, clara y consistente para la comparación de los resultados de problemas multi-objetivo. Para comenzar el recorrido por el taller de flujo planteamos una tarea que nunca se ha llevado a cabo hasta la fecha: la implementación y comparación experimental de 23 algoritmos multi-objetivo. Alguno de ellos propuestos para el taller de flujo multi-objetivo y otros de carácter general. Esto nos dará un importante punto de partida para conocer las metodologías existentes en la literatura parar resolver problemas multiobjetivo. Como resultado conoceremos metodologías que van desde algoritmos genéticos, pasando por la búsqueda tabú, colonias de hormigas, recocido simulado, etc. Todo este trabajo inicial nos permitirá ver las ventajas y desventajas de cada método propuesto y determinar los puntos fuertes de los mejores para, finalmente, proponer un método de resolución de problemas de taller de flujo general, eficaz y eficiente. El recorrido por distintos problemas de taller de flujo nos permitirá conocer el estado actual de la literatura y acercarnos paso a paso a los problemas que mejor representan la realidad. En cada paso realizaremos un profundo estudio del estado actual de la literatura, comparando los métodos existentes contra un método propuesto por nosotros mismos. En este aspecto partiremos del problema del taller de flujo de permutación multi-objetivo, luego ampliaremos este problema añadiéndole tiempos de cambio dependientes de la secuencia y finalmente estudiaremos el problema del taller de flujo híbrido multi-objetivo.Minella, GG. (2014). Optimización multi-objetivo para la programación de la producción [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37980TESI

Malting barley BRS Borema

BRS Borema is an early maturing, two-rowed spring barley registered in 2003 for commercial production inSouthern Brazil, bred by Embrapa Trigo. It combines good yield potential with superior malting quality and a reasonable levelof disease (net blotch, powdery mildew, leaf rust) resistance. It is well-adapted to all major production regions of maltingbarley in Brazil

BRS 180: malting barley for irrigated plantation in the Brazilian Savannah

Culturas alternativas de inverno com viabilidade técnica e econômica para integrar os sistemas de produção irrigados constituem-se na principal demanda dos agricultores da região do Cerrado. A cultivar de cevada BRS 180 obtida pela Embrapa-Centro Nacional de Pesquisa de Trigo e Embrapa-Centro de Pesquisa Agropecuária dos Cerrados, lançada para o cultivo irrigado em 1999, representa a primeira cultivar adaptada para a região, potencializando essa cultura como uma nova opção para o produtor. BRS 180 apresenta elevados índices de produtividade, resistência ao acamamento e baixos teores de proteínas, o que vem atender às demandas agronômicas dos agricultores e aos padrões de qualidade da indústria de malte cervejeiro. Em parcelas experimentais, BRS 180 apresentou rendimentos de grãos de até 8.920 kg/ha, atingindo até 6.000 kg/ha em lavouras comerciais.Alternative economic and technically viable crop species are very needed for the production systems under irrigation in the Cerrado of central Brazil. Barley BRS 180 released by Embrapa-Centro Nacional de Pesquisa de Trigo and Embrapa-Centro de Pesquisa Agropecuária dos Cerrados in 1999, the first adapted cultivar developed for the region, potentializes malting barley as new crop alternative for the growers in the Cerrados. BRS 180 has shown high yield potential, lodging resistance and low protein levels, fulfilling the demands of both growers and malting barley industries. The observed yield potential of BRS 180 was up to 8,920 kg/ha in experimental plots and 6,000 kg/ha in commercial farm fields

Barley cultivar BR 2: malting quality and resistance to net blotch caused by Pyrenophora teres

A Cevada BR 2, criada pela Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), foi lançada para cultivo em 1989. Originou-se de sete plantas selecionadas em F3 do cruzamento FM 424/TR 206, realizado em 1979, em Passo Fundo, RS. A BR 2 é uma cevada de primavera, do tipo de duas fileiras de grãos, com ciclo precoce, ampla adaptação e porte baixo. É a primeira cultivar brasileira resistente a Pyrenophora teres, agente causal da mancha-reticular, principal moléstia da cevada no Brasil. Em oito anos de avaliação no Ensaio Nacional de Cevada, conduzido em 12 locais da Região Sul, a BR 2 rendeu entre 1.621 e 4.014 kg/ha de grãos de primeira qualidade, superando a cultivar Antarctica 05 em 3% no RS e SC, em 13% no PR, e em 6% na média dos 96 experimentos (12 locais x 8 anos). Na lavoura, a BR 2 tem produzido rendimentos acima de 5.000 kg/ha. Aprovada como cervejeira em 1992, ocupou 30% da área semeada em 1993 e 90% em 1997. A BR 2 representa um marco no progresso do melhoramento genético da cevada no país, contribuindo decisivamente para o aumento da competitividade da produção doméstica.Barley cultivar BR 2 developed by the Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT) was released in 1989. BR 2 traces back to seven plants selected in the F3 from the cross FM 424/TR 206 made in Passo Fundo, RS, in 1979. BR 2 is a two row spring barley with wide adaptation, earliness and short straw. It is the first Brazilian cultivar resistant to Pyrenophora teres, causal agent of net blotch, a major barley disease in Brazil. In eight years of yield testing in the National Barley Trial in twelve locations of Southern Brazil, BR 2 yielded between 1,621and 4,014 kg/ha of plump kernels, with 3%, 13% and 6% yield increase over the check cultivar Antarctica 05 in the States of Rio Grande do Sul and Santa Catarina, Paraná and in the mean of 96 trials, respectively. On the farm fields, BR 2 has yielded over 5,000 kg/ha. Since its approval as a malting barley in 1992, it has been widely used, taking up 30% in 1993 and 90% in 1997 of the area sown. Barley BR 2 represents a cornerstone in the history of barley breeding in Brazil and is making a significant contribution to the competitiveness of the domestic barley production

Multi-objective sequence dependent setup times permutation flowshop: A new algorithm and a comprehensive study

The permutation flowshop scheduling problem has been thoroughly studied in recent decades, both from single objective as well as from multi-objective perspectives. To the best of our knowledge, little has been done regarding the multi-objective flowshop with Pareto approach when sequence dependent setup times are considered. As setup times and multi-criteria problems are important in industry, we must focus on this area. We propose a simple, yet powerful algorithm for the sequence dependent setup times flowshop problem with several criteria. The presented method is referred to as Restarted Iterated Pareto Greedy or RIPG and is compared against the best performing approaches from the relevant literature. Comprehensive computational and statistical analyses are carried out in order to demonstrate that the proposed RIPG method clearly outperforms all other algorithms and, as a consequence, it is a state-of- art method for this important and practical scheduling problemThe authors thank the anonymous referees for their careful and detailed comments which have helped improve this manuscript considerably. This work is partially financed by the Spanish Ministry of Science and Innovation, under the projects "SMPA-Advanced Parallel Multiobjective Sequencing: Practical and Theorerical Advances" with reference DPI2008-03511/DPI and "RESULT-Realistic Extended Scheduling Using Light Techniques" with reference DPI2012-36243-C02-01 and by the Small and Medium Industry of the Generalitat Valenciana (IMPIVA) and by the European Union through the European Regional Development Fund (FEDER) inside the R+D program "Ayudas dirigidas a Institutos Tecnologicos de la Red IMPIVA" during the year 2011, with project numbers IMDEEA/2011/142 and IMDEEA/2012/143.Ciavotta, M.; Minella, GG.; Ruiz García, R. (2013). Multi-objective sequence dependent setup times permutation flowshop: A new algorithm and a comprehensive study. European Journal of Operational Research. 227(2):301-313. https://doi.org/10.1016/j.ejor.2012.12.031S301313227

Restarted Iterated Pareto Greedy algorithm for multi-objective flowshop scheduling problems

Multi-objective optimisation problems have seen a large impulse in the last decades. Many new techniques for solving distinct variants of multi-objective problems have been proposed. Production scheduling, as with other operations management fields, is no different. The flowshop problem is among the most widely studied scheduling settings. Recently, the Iterated Greedy methodology for solving the single-objective version of the flowshop problem has produced state-of-the-art results. This paper proposes a new algorithm based on Iterated Greedy technique for solving the multi-objective permutation flowshop problem. This algorithm is characterised by an effective initialisation of the population, management of the Pareto front, and a specially tailored local search, among other things. The proposed multi-objective Iterated Greedy method is shown to outperform other recent approaches in comprehensive computational and statistical tests that comprise a large number of instances with objectives involving makespan, tardiness and flowtime. Lastly, we use a novel graphical tool to compare the performances of stochastic Pareto fronts based on Empirical Attainment Functions. © 2011 Elsevier Ltd.The authors are indebted to the anonymous referees for their helpful comments which have helped in improving an earlier version of this manuscript. This work is partially funded by the Spanish Ministry of Science and Innovation, under the projects "SMPA - Advanced Parallel Multiobjective Sequencing: Practical and Theoretical Advances" with reference DPI2008-03511/DPI. The authors should also thank the IMPIVA - Institute for the Small and Medium Valencian Enterprise, for the project OSC with references IMIDIC/2008/137, IMIDIC/2009/198 and IMIDIC/2010/175 and the Polytechnic University of Valencia, for the project PPAR with reference 3147.Minella, GG.; Ruiz García, R.; Ciavotta, M. (2011). Restarted Iterated Pareto Greedy algorithm for multi-objective flowshop scheduling problems. Computers and Operations Research. 38(11):1521-1533. https://doi.org/10.1016/j.cor.2011.01.010S15211533381

Barley cultivar BRS Mariana

BRS Mariana is an early-maturing, two-rowed spring barley registered in 2005 for commercial production insouthern Brazil. Its features good biomass and grain yield potential as well as disease resistance (to net blotch, powderymildew, leaf rust). It is well adapted to all major barley production regions of southern Brazil but achieves full yield potentialin the state of Paran

BRS 180: cevada cervejeira para cultivo irrigado no Cerrado

Culturas alternativas de inverno com viabilidade técnica e econômica para integrar os sistemas de produção irrigados constituem-se na principal demanda dos agricultores da região do Cerrado. A cultivar de cevada BRS 180 obtida pela Embrapa-Centro Nacional de Pesquisa de Trigo e Embrapa-Centro de Pesquisa Agropecuária dos Cerrados, lançada para o cultivo irrigado em 1999, representa a primeira cultivar adaptada para a região, potencializando essa cultura como uma nova opção para o produtor. BRS 180 apresenta elevados índices de produtividade, resistência ao acamamento e baixos teores de proteínas, o que vem atender às demandas agronômicas dos agricultores e aos padrões de qualidade da indústria de malte cervejeiro. Em parcelas experimentais, BRS 180 apresentou rendimentos de grãos de até 8.920 kg/ha, atingindo até 6.000 kg/ha em lavouras comerciais

E Minella et al. Malting barley BRS Borema

ABSTRACT -BR