2020 Volume 71 Issue 1 Pages 35-46
It is very important to increase the productivity of picking operations in e-commerce in order to satisfy customer demand in the shortest possible time. There are two work methods for shipping, order picking and inverse order picking, that are commonly used in distribution centers. An inverse order picking system has two major tasks before shipping. One is picking the total amount of each item from the shelves, and the other is properly placing items into the correct container based on the customer that ordered them. This placement operation is also called “sorting”. In a traditional sorting method, the workers place items into the container by type one at a time. When there are many different types of items, workers must walk long distances because the route the worker must walk is decided based on each type required to fill the order. In this paper, we propose a sorting method that consolidates multiple types of apparel items. Walking time is reduced by consolidating items together. However, the selection time increases because worker must choose the items required, sorting them out from multiple items. Therefore, it is not easy to determine which sorting method is best. In this paper, we reveal the effect of make-span and total working time, such as walking time and blocking time using simulation. The simulation approach is effective in modeling blocking. The experimental results indicate that the sorting method needs to be selected according to situation and purpose.
