2019 Volume 69 Issue 4 Pages 184-193
To reduce costly order picking activities, many companies configure their warehouse with a forward area and a reserve area. The former is a small area where the most popular parts can be conveniently picked. The latter is used for replenishing the forward area and storing parts that are not assigned to the forward area. As pickers consume the inventory in the racks, there is a risk of stockout. Having sufficient inventories in the forward area of a warehouse is essential for warehouse operations. Parts are replenished using a forklift because of their heaviness. Multiple parts can be replenished at the same time, but depending on the combination of parts to be replenished, unnecessary working time may occur. Reducing the number of parts stored in the forward area enables a more compact forward area, thus reducing picking effort there, but requires more frequent replenishment from the reserve area to the forward area. Based on real data, this paper studies setting the reorder level and determining the combinations of parts to be replenished in order to reduce working time in the warehouse of an automotive factory. We model this problem as an integer programming problem. Furthermore, we present an algorithm to estimate working time quickly, even in the case of a large-scale problem.
