Order picking can be defined as the retrieval of stock keeping units from a warehouse according to a pick list generated from a customer order prior to the despatch of the completed order to the customer. There is a variety of order picking systems that are used in warehouses and distribution centres and the choice of system will determine the amount and type of manual handling that occurs within those locations. In order to understand the factors that influence the design of order picking systems a literature review was undertaken and telephone interviews were conducted with six industry stakeholders. The stakeholders included were two retailers with distribution networks operating across the UK, two specifiers who design order picking systems of different types and complexity for the end users, and two major suppliers of order picking systems.
The factors that influence the amount of manual handling within warehouses and distribution centres are complex and inter-locking. The key factor is the design of the order picking system, particularly how much automation is used and whether pickers travel between pick slots or whether items are automatically delivered to them. It also depends on the nature of the goods that the warehouse handles. There are financial trade-offs between high capital costs of automated systems, and increased labour costs in manual systems.