What is picking? Picking methods in warehouses

We have discussed at length how to organise a warehouse efficiently, and one of the conclusions is that picking products from the shelves for delivery is one of the sticking points. You need to optimize this operation to increase efficiency across the whole warehouse activity. Here are the most important details on picking, so you can choose the best picking methods for the warehouses you manage.

What is picking?

The operations of “taking” products from the shelf or selecting ordered goods from warehouse stocks for delivery are described in the logistics field by the term picking. This important stage is considered the weakest link in warehousing because it is a laborious activity involving various actions and significant costs.

It is estimated that more than 50% of operational costs in warehouses and distribution centers are incurred during the picking stage. The organization of flows in logistics centers and stock management are directly influenced by the way picking is carried out.

The way products are picked and grouped by order has a direct impact on customer satisfaction. This is why logistics companies focus on the quality of picking in terms of efficiency, speed and accuracy.

What are the main picking methods in warehouses?

Picking can be carried out in different ways depending on the volume of activity and stocks, size of the warehouse, ABC classes, number of employees, complexity or order profile. Automation is often used to increase efficiency.

Here are the main picking methods used to streamline picking and optimize warehouses in different industries.

Single Order Picking

Single order picking, also known as discrete order picking, is the simplest method of picking and involves picking one order at a time. The picker goes to the warehouse and collects all the specified items from a single order. After picking one order is complete, the worker starts picking another. There is no picking schedule, orders can be picked as soon as they are received.

This method is advantageous in terms of its simplicity, speed of order collection and ease of tracking picking accuracy for each worker.

Of course, there are not only advantages. With order-picking, workers lose much more time than with other methods. Pickers travel longer distances because they do not pick items from several orders at the same time. Because of this, productivity is low, labor costs are higher, and the pace of deliveries, slow. From this point of view, single order picking is not recommended for large warehouses or warehouses with high daily order volumes.

To optimize this type of picking, digitization can be used, either through the implementation of WMS systems or through the use of appropriate equipment/forklifts/carts that facilitate the picking of items from the warehouse, help reduce errors and increase productivity.

Batch Picking

By using this method, a warehouse worker picks the same stock keeping units (SKUs) for multiple orders at the same time. After picking, items are separated for each order in the packing area and made ready for delivery.

This method is particularly advisable when the same items are found in several orders. In these circumstances, a picker moves only once to collect the same type of product for multiple orders. Batch picking has the advantage that the time taken to collect a series (batch) of orders is significantly reduced, productivity is increased and deliveries get faster.

Grouping orders according to the items ordered helps to both optimize and ensure the accuracy of the batch picking process. In general, the method is particularly effective in smaller warehouses, where orders are placed for a low number of small items.

Cluster Picking

Cluster picking is a method similar to batch picking, differing from it only in the distribution of items with the same SKU collected. Whereas in batch picking all items with the same SKU are collected in one container and then separated by order and placed in several containers, in cluster picking they are collected separately in containers which are moved through the warehouse and to which the other items are gradually added (in waves of items with the same SKU). This means that, during cluster picking, the grouping by order of items with the same SKU is done from the very beginning, not afterwards.

Zone picking

The zone picking method involves first dividing the warehouse into zones. Each picker is allocated a zone from which they will collect all the ordered products that are stored there. Once the picking of items from a zone is completed, the trolley is handed over to another picker who adds the requested items from the zone he is in charge of, and so on, until all the items specified in the received orders are collected.

For example, an employee starts picking all the items with the same requested SKUs that are in zone A, then passes the trolley on to a picker in zone B, and so on. (Of course, the zones where the requested items are stored are taken into account.) The process is repeated until the order is fully picked and sent for shipment. Because the method is based on “picking and passing orders” from one zone to another, this type of picking is also known as Pick & Pass.

With this method, a simple scheduling is done: orders received by a certain time (cutoff time) are picked during the same shift, whereas those received after the cutoff are picked in the following shift.

Zone picking allows the use of different technologies, depending on the specific activity in each zone. WMS warehouse management systems can be implemented so that items picked in each zone are collected, checked and grouped into individual orders before delivery.

Zone-Batch Picking

Zone-batch picking is a method that combines the features of the two methods specified in its name: each picker is responsible for one zone, as in zone picking, but collects orders according to the batch picking method.

In other words, each picker collects, in their zone, the items with the same SKU from the orders they handle at the same time, and after batch picking in that zone is completed, the process is continued in another zone by the picker who is in charge of it.

In this combined method, picking activities are scheduled according to the time intervals in which orders are received.

Wave picking

The wave picking method involves collecting orders in waves. Orders received within a certain time frame represent one of the ‘waves’ that are collected at the same time. Picking is done daily, in several waves, depending on the number of time intervals set for the receipt of orders.

Thus, wave picking is a method of order processing that focuses on the time of order picking and it is based on grouping items according to a variety of criteria such as courier, carrier, customer or returnable packaging required for transport. After grouping, orders are picked only at certain times of the day.

Improving team efficiency is based on reducing (or eliminating) under-utilized working time. A wave of orders is picked at intervals of between 45 minutes and 2 hours, depending on the warehouse and the type of products to be taken from the shelves. After picking, all products are taken to the sorting area and grouped by individual orders.

Zone-Wave Picking

Zone-Wave Picking is another mixed method resulting from the combination of zone picking and wave picking.  Every picker is allocated a zone and collects all the items stored in their zone for all orders, one by one, with one scheduled window per shift.

Zone-Batch-Wave Picking

This is the most complex method, being the result of combining three picking methods. In other words, each picker is assigned a zone where they picks multiple items with the same SKU, for multiple orders at once. Picking is also done in waves, with multiple picking intervals per shift.

Picking optimization

The optimization of any picking method can be achieved through the implementation of WMS software solutions, coupled with the use of handheld terminals for data capture, reading and playback. Digitization of data flows related to warehouse work processes ensures data collection and automatic processing, accuracy of information, traceability of warehouse items and stock management.

In the case of picking, optimization means, in general terms: shortening the routes taken by pickers inside the warehouse, introducing paperless picking, identifying products correctly and quickly, reducing the number of errors and subsequent returns as well as the time taken to pick each order, increasing productivity.

Axes Software has created innovative and customizable software solutions for warehouse management in order to support 3PL or warehousing companies. By using them, you will increase the efficiency of the picking methods you use. You’ll benefit from the integration of warehouse management software solutions with other systems and technologies (pick by voice, pick by light technologies), and you’ll be able to access the xTrack WMS cloud-hosted version.

If you need more details on the possibilities of optimizing picking activities through our xTrack WMS application, you can send us a message by filling in one of the forms on the website. We will contact you within 48 hours.