Application of Tabu-Search-Based Method to Order Batching and Routing Problems in Logistics Warehouses

The order batching problem and the picker routing problem are methods for improving the efficiency of order picking operations in logistics warehouses. The former is a problem to optimize the combination of multiple orders for efficient picking, and the latter is a problem to optimize the route for picking batches, which are a sets of combined orders. Both problems have been formulated as mathematical optimization problems to minimize the total travel distance, and have been the subject of numerous previous studies. However, when the scale of the problem is large, it is often impossible to obtain an exact solution in a practical time, and even a feasible approximate solution cannot be obtained. In this study, we propose a new optimization algorithm based on the tabu-search method, a meta-heuristic, for the batching and routing problems in logistics warehouses, where the order batching and picker routing problems are considered simultaneously. The effectiveness of the proposed method is verified through a large number of numerical experiments using large-scale problem data prepared with reference to real data.