Improved formulations of the joint order batching and picker routing problem

Order picking is the process of retrieving ordered products from storage locations in warehouses. In picker-to-parts order systems, two or more customer orders may be grouped and assigned to a single picker. Then routing decisions regarding visiting sequence items during tour must made. Won Olafsson (2005) found that solving integrated problem batching enables warehouse managers organize operations efficiently compared with problems separately sequentially. We therefore investigate mathematical programming formulation this problem.We present several improved formulations based on findings Valle, Beasley, Salles da Cunha (2017), can significantly improve computational results. More specifically, we reconstruct connectivity constraints generate new cutting planes our branch-and-cut framework. also discuss some properties by studying structure graphical representation warehouse, types additional constraints. consider no-reversal case problem. efficient building different auxiliary graphs. Finally, results for publicly available test single-block multiple-block configurations.