6. Order Batching in Order Picking Warehouses: A Survey of Solution Approaches

Order picking is a warehouse function dealing with the retrieval of articles from their storage locations in order to satisfy a given demand specified by customer orders. Of all warehouse operations, order picking is considered to include the most cost-intensive ones. Even though there have been various attempts to automate the picking process, manual order picking systems are still prevalent in practice. This chapter will focus on order batching, a central planning issue in order picking systems. Order batching has been proven to be pivotal for the efficiency of order picking operations. Improved order batching reduces the total picking time required to collect the requested articles. According to experience from practice, this can result in significant savings of labour cost and in a reduction of the customer order’s delivery lead time. The aim of this contribution is to provide comprehensive insights into order batching by giving a detailed state-of-the-art overview of the different solution approaches which have been suggested in the literature. Corresponding to the available publications, the emphasis will be on static order batching. In addition to this, the chapter will also review the existing literature for variants and extensions of static order batching. Furthermore, solution approaches for dynamic order batching problems will be presented.