Investigating the impact of heavy products allocation on picker routing policies in a warehouse setting

In department stores, heavier products, such as water, are assigned to specific areas, placing them first in pallets to avoid the damage of lighter products that complete the picking order and are put over these heavier products. This study analyses the impact of the allocation of heavy products and of the size of relating areas on picker routing policies, and compare this scenario with a situation in which an area dedicated to heavy product does not exist in the warehouse. S-Shaped and S-Shaped Advanced policies are implemented to respond to picking orders for different products to be allocated in pallets following rules dictated according to their weight. Through a simulative approach, conducted with MS ExcelTM software, their joint implementation was simulated by distinguishing various allocation areas within the warehouse to simulate the different types of products to be picked; the objectives functions cover the minimization of routes to fulfil orders, and the minimization of the total travelled distance. Warehouse storage capacity, picking list size, and the size of the specific allocations were the variables considered. The results of the two scenarios are presented separately and in aggregate form to appraise: (i) the impact of heavy product-specific allocation, (ii) the efficiency of the proposed solutions in terms of the total distance travelled by the pickers, and (iii) the achievable optimization margins. Finally, a possible future research proposal is presented. © 2023 The Authors.