A warehouse needs to have sufficient open locations to be able to store incoming shipments of various sizes. In combination with ongoing load retrievals open locations gradually spread over the storage area. Unfavorable positions of open locations negatively impact the average load retrieval...

In this paper, we discuss an approximation method based on G/G/m queuing network modeling using Whitt's (1983) queuing network analyzer to analyze pick-and-pass order picking systems. The objective of this approximation method is to provide an instrument for obtaining rapid performance estimates...

Customer order response time and system throughput capacity are key performance measures in warehouses, which depend strongly on the storage strategies deployed. One popular strategy is to split inventory into a bulk storage and a pick stock, or forward-reserve (FR) storage. Managers often use a...

Improving on existing products is an effective product differentiation strategy for firms. We refer to such improved products as next-generation products (NGPs). Research shows that 40% of product transitions fail and that some lead to bankruptcies. Bad timing is often mentioned as one of the...

We study the case of a catalogue/internet mail order retailer selling seasonal productsand receiving large numbers of commercial returns. Returned products arriving beforethe end of the selling season can be resold if there is sufficient demand. A single orderis placed before the season starts....

The order batching problem (OBP) is the problem of determining the number of orders to be picked together in one picking tour. Although various objectives may arise in practice, minimizing the average throughput time of a random order is a common concern. In this paper, we consider the OBP for a...

Internal transport systems using automated guided vehicles (AGVs) are widely used in many facilities such as warehouses, distribution centers and transshipment terminals. Most AGV systems use online dispatching rules to control vehicle movements. In literature, there are many types of...

In the warehouse of Ankor, a wholesaler of tools and garden equipment, various problems concerning the storage and retrieval of products arise. For example, heavy products have to be retrieved prior to light products to prevent damage. Furthermore, the layout of the warehouse differs from the...

Already for a long time retailers take back products. In this paper we explore the factors contributing to the decision of combining vs. separating inbound and outbound flows during the return handling process. We do so through a comparative analysis of the operations in nine retailer...

Warehouse operations are rapidly becoming more robotized to increase performance and cut costs. One important new way of working is in collaboration between humans and robots. However, even though humans and their behavior remain essential for operational performance, human factors in...