Determining an optimal route for order picking in narrow aisles with deadlines and congestion factors

Abstract

The order picking process typically contributes to the success of any warehouse management. In any warehouse operation, order picking contributes more than 60% of labor activities and 50% of the direct labor costs. Various variables can affect the productivity of the picking process, such as warehouse layout, number of order pickers, and different routing methods. In actual warehouse activities, each order is often set with specific due times in same-day picking, and many orders are grouped into different batches to reduce the traveling time. If any orders are late retrieved after due times, tardiness could occur. Additionally, one factor should also be considered congestion in the warehouse. All of the above variables are tested in this thesis by combining a heuristic and exact optimization mathematical model to determine the optimal route for order picking to minimize the tardiness by late order release. The results show a reduction in the total distance by 17.32% in comparison with the current traditional routing method. Then some solutions and recommendations will be proposed to provide a complete picture of order picking improvement. To support this thesis, the proposed solution model is applied for the warehouse of ABC company in small computer components products.