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 procedure in which order control and picking are not carried out immediately, but in two stages. Depending on the type of warehouse 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-stage picking is a certain quantity of individual customer orders (goods) that can be combined into a total order (order pool or batch).
The merchandise management or warehouse management system accumulates the orders together and calculates the optimal 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 (optimisation of walking times). The picker places the items 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 item is scanned and sorted with the help of a distribution system.
The picking process is only completed after the two-stage sorting.
Two-stage picking is very suitable for large total quantities of orders. The advantage here is that thepicker can remove many items from a storage compartment at the same time. A large order is split up. This saves the picker the distances. The 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. To do this, each item is scanned and assigned to the appropriate order.
Two-stage picking is very effective, but requires complex technical support and a large total quantity of customer orders for the individual order. This is where the process differs significantly from single-stage picking. Picking can also be carried out by untrained staff.
The supporting systems
Two-stage picking cannot be realised 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.
You can find out more details in the following articles:
Pick-to-Light - picking with compartment displays
Voice Picking - voice-guidedpicking
Pick-by-Point - the simple picking method with light
Pick-by-Frame - the innovation for Multi-Order-Picking
Picking time, partial orders, storage space, dead time, picking time, base time, picking performance, order throughput times, distribution time, compilation, lead times.