Title: Genetic algorithms with different representation schemes for complex hybrid flexible flow line problems

Authors: Thijs Urlings, Ruben Ruiz, Funda Sivrikaya Serifoglu

Addresses: Grupo de Sistemas de Optimizacion Aplicada, Instituto Tecnologico de Informatica, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain. ' Grupo de Sistemas de Optimizacion Aplicada, Instituto Tecnologico de Informatica, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain. ' Duzce University, Konuralp Yerleskesi, Duzce, 81620 Turkey

Abstract: This paper introduces some advanced genetic algorithms for a complex hybrid flexible flow line problem with a makespan objective that was recently formulated. General precedence constraints among jobs are taken into account, as are machine release dates, time lags and sequence dependent set-up times; both anticipatory and non-anticipatory. This combination of constraints captures many real world industrial problems; among those is the ceramic tile production that served as our inspiration. The introduced algorithms employ solution representation schemes with different degrees of directness. Several new machine assignment rules are introduced and implemented in some proposed genetic algorithms. The different genetic algorithms are compared among each other and to some heuristics as well. The results indicate that simple solution representation schemes result in the best performance, even for complex scheduling problems and that the genetic algorithms lead to a better solution quality than all tested heuristics.

Keywords: hybrid flexible flow lines; HFFL; realistic scheduling; genetic algorithms; GAs; precedence constraints; setup times; time lags; ceramic tiles; tile production; metaheuristics.

DOI: 10.1504/IJMHEUR.2010.033122

International Journal of Metaheuristics, 2010 Vol.1 No.1, pp.30 - 54

Published online: 08 May 2010 *

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