The VDI guideline 3590 defines the term picking as "the compilation of certain partial quantities (articles) from a provided total quantity (assortment) based on demand information (orders)." The items to be picked can be raw materials and auxiliary materials as well as semi-finished and finished products.
The selected picking process is based on the time and space requirements with regard to the provision of goods, their removal and delivery. Suitable picking techniques can be derived from this and implemented as a system solution. Picking systems are generally categorized as follows:
- Information system
- Organization system
- Material flow system
The information required for order processing can be transmitted either acoustically (pick-by-voice), optically (pick-by-light) or by radio data transmission. The material flow system regulates the provision of goods either according to the "person-to-goods" or "goods-to-person" principles, requires manual or automatically supported removal and therefore directly influences the movement sequences of the employees. The organizational system, on the other hand, focuses on the structural and process organization within order picking and its optimization.