To cite this version:François Clautiaux, Ruslan Sadykov, François Vanderbeck, Quentin Viaud. Pattern based diving heuristics for a two-dimensional guillotine cutting-stock problem with leftovers.
AbstractWe consider a variant of two-dimensional guillotine cutting-stock problem that arises when different bills of order (or batches) are considered consecutively. The raw material leftover of the last cutting pattern is not counted as waste as it can be reused for cutting the next batch. The objective is thus to maximize the length of the leftover. We propose a diving heuristic based on a Dantzig-Wolfe reformulation solved by column generation in which the pricing problem is solved using dynamic programming (DP). This DP generates so-called nonproper columns, i.e. cutting patterns that cannot participate in a feasible integer solution of the problem. We show how to adapt the standard diving heuristic to this "non-proper" case while keeping its effectiveness. We also introduce the partial enumeration technique, which is designed to reduce the number of nonproper patterns in the solution space of the dynamic program. This technique helps to strengthen the lower bounds obtained by column generation and improve the quality of solutions found by the diving heuristic. Computational results are reported and compared on classical benchmarks from the literature as well as on new instances inspired from industrial data. According to these results, proposed diving algorithms outperform constructive and evolutionary heuristics.The paper is organised as follows. We first give an overview of the literature on related problems in Section 2. Then in Section 3, we recall how it can be modelled by an exponentially large ILP model in which each variable represents a cutting pattern, and how the pricing subproblem can be solved by dynamic programming. Constructive and evolutionary heuristics inspired from the literature for the 2DGCSPL are discussed in Section 4. In Section 5 we present our 2 pattern based diving heuristics for the 2DGCSPL. To obtain better solutions by these diving heuristics, we also propose a partial enumeration technique that is embedded in the dynamic program for solving the pricing subproblem. In Section 6, we report results of computational experiments in which we compare different heuristic algorithms on classical data sets and real-life instances. Conclusions are drawn in Section 7.
Literature reviewCutting-stock problems have drawn a large attention because of their significance for the industry, and their theoretical and practical difficulty. When all demands are unitary (d i " 1, @i P I), the problem is also referred in the literature as the bin-packing problem. From a theoretical point of view, one can reformulate a bin-packing problem as a cutting-stock problem, therefore through the rest of this paper, we will use both names.The first study on two-dimensional packing problems appeared in Gilmore and Gomory [13]. Therein, the approach is to formulate the two-dimensional bin-packing problem (2BP) using Line...