RT info:eu-repo/semantics/article T1 Minimizing the waiting times of block retrieval operations in stacking facilities A1 López Plata, Israel A1 Expósito Izquierdo, Cristofer Juan A1 Lalla Ruiz, Eduardo Aníbal A1 Melián Batista, María Belén A1 Moreno Vega, José Marcos A2 Ingeniería Informática y de Sistemas K1 Blocks Relocation Problem with Waiting Times K1 Stacking crane K1 Optimization model K1 Heuristic AB This paper addresses the Blocks Relocation Problem with Waiting Times. Its objective is to retrieve a set of homogeneous blocks from a two-dimensional storage by minimizing the waiting times during their retrieval. An integer programming model and a heuristic algorithm are developed to solve this optimization problem. The mathematical model is able to solve small-size cases to optimality in reasonable computational times. Unfortunately, it requires large computational times when tackling medium and largesize scenarios. For its part, the heuristic algorithm overcomes the problems associated with the computational burden of the model by bringing forward the availability of blocks to retrieve from the storage. With this goal in mind, several look ahead strategies dedicated to perform the most promising predictive block relocation movements are proposed. The computational results disclose the proposed heuristic algorithm is able to report high-quality solutions through very short computational times, less than one second, in practical cases. YR 2017 FD 2017 LK http://riull.ull.es/xmlui/handle/915/40328 UL http://riull.ull.es/xmlui/handle/915/40328 LA en DS Repositorio institucional de la Universidad de La Laguna RD 18-dic-2024