A More Concise and Efficient Formulation of Order Picker Routing in a Rectangular Single-Block Warehouse

Order picker routing in a rectangular single-block (conventional) warehouse is a classical and fundamental logistics problem. Exact algorithm with linear computational complexity exists, and it has also been frequently extended to non-conventional warehouses. This paper proposes a new and more concise formulation of the order picker routing in the conventional warehouse. It is easier to present and understand, based on which the algorithm can be implemented in a more concise way and the computation is more efficient. Viewed as an improvement of existing methods for the order picker routing problem in conventional warehouses, the new formulation and corresponding algorithm have potential to be adopted in non-conventional warehouses.