In this article we describe two-stage picking in logistics and show you the advantages and disadvantages of the process.
What is two-stage picking?
Two-stage picking is a picking process in which order control and picking are not carried out immediately, but in two stages. Depending on the storage type and storage zones, the orders are first picked cumulatively by the picker and then distributed to the individual orders at the packing station. The process is often supported by a sorting system.
How exactly does the process work?
The prerequisite for two-step picking is a certain quantity of individual sales orders (goods) that can be grouped together to form a total order (order pool or batch).
The merchandise management or warehouse management system cumulates the orders together and calculates the optimum combination of orders. In this picking process, the volume of the items and the containers must also be taken into account.
The storage type is crucial for the management, or more precisely for the wave management of two-stage picking. In intralogistics, the goods issue process and return storage is often supported by distribution systems (sorters) to simplify sorting at the second stage.
1st stage of two-stage picking
In the first stage of two-stage picking, the picker collects as many items (goods) as possible from a storage compartment in the storage zone, item by item. This saves him walking through several picking zones (optimization of walking times). The picker places the articles in one or more boxes (but it is not Multi-Order-Picking).
The decisive factor here is that the order picker counts the correct number of items on an item-by-item basis when picking.
2nd stage of two-stage picking
Once the removal of the items in the warehouse is complete, the picker transports his boxes to a distribution station for sorting. Only there does the order-oriented sorting to the individual customer orders take place. Each article is scanned and sorted with the help of a distribution system.
The picking process is only completed after the two-stage sortation.
Two-stage picking is very suitable for large total quantities of orders. The advantage here is that the picker(order picker) can pick many items from one storage compartment at the same time. A large order is split up. This saves the picker the distances. Disadvantage compared to single-stage picking is that the picker may have to count out large numbers of items from a storage compartment, although the possible error is not very critical here.
In the second stage, the articles are assigned to the orders with a distribution system. For this purpose, each article is scanned and assigned to the appropriate order.
Two-step picking is very effective, but requires complex technical support and for the single order a large total amount of customer orders. Here the procedure differs significantly from the single-stage picking. Picking can also be performed by untrained personnel.
The supporting systems
Two-stage picking cannot be implemented without the support of picking systems. Various systems such as: Pick-to-Light, Voice Picking, Pick-by-Point®, Pick-by-Frame®, etc. are used for support here.
Further details can be found in the following articles:
Pick-to-Light - picking with compartment displays
Voice Picking - voice-guided picking
Pick-by-Point - the simple picking method with light
Pick-by-Frame - the innovation for Multi-Order-Picking
Picking time, partial orders, storage location, dead time, picking time, base time, picking performance, order lead times, distribution time, compilation, lead times.