Effect of picker congestion on travel time in an order picking operation

抄録

In recent years, customer needs have diversified and companies have been forced to deliver products quickly to their customers. Distribution warehouses play an important role in improving the efficiency of the entire supply chain, and improving the efficiency of the order preparation operation, otherwise known as order picking, is therefore essential. This research models an order picking operation in which two or more pickers are operating simultaneously, and the optimal design for operation efficiency is analyzed. Here, the picker targets multi-picking, which entails the collection of multiple products in one tour, and the picker always selects the shortest route for collecting the products. In this research, the behavior of the pickers is modeled using a multi-agent system, such that multiple pickers pass one another in the warehouse and a conflict due to excessive congestion is reproduced. The effect prompted by changes to both the layout and the storage assignment using the aforementioned model was clarified. The simulation results show that an optimal warehouse design based on warehouse characteristics (picking area size and differences in the demand frequency of each product) and the number of pickers operating simultaneously significantly affects the efficiency of the order picking operation. Furthermore, it is possible to reduce picker travel time by using the class storage method. The greater the difference in the demand frequency of each product, the greater the effect.