Picking explained: Systems, processes and advantages

Picking is one of the essential processes in logistics and critical to a company’s success – after all, error-free and on-time order fulfillment keeps customers happy and helps businesses maintain a competitive edge. This article shows you what picking really entails, what systems and processes exist for the perfect pick, and which solution is best for you. [By Lisa Gruber]

Picking can be defined as the compilation of specific items from an assortment to fulfil a given order.

In short: Picking is the process by which goods are made available. The orders may vary, but the process remains the same: If a customer purchases a product from an online retailer, for example, this order must be picked in the exact same way as an order from manufacturing for the provision of materials. The employee who carries out the picking holds a lot of names, e.g. warehouse clerk or warehouse worker, handler or packer.

As good picking means good customer service, fast, efficient, and accurate logistics processes are important for any company. Accurate order processing is often the decisive factor in terms of competitiveness and thus revenue. And the costs of imperfect order fulfilment can be high: When the wrong parts are delivered to a production line, the entire manufacturing process comes to a halt until the right items can be properly provided.

But picking is usually very labor and cost intensive. That is why companies are always investigating how to reduce expenses, streamline their processes, and increase the quality of order picking.

The Basics: Picking Systems

There are two different types of picking systems: automatic and manual.

Automated order picking

Automated picking systems reduce the need for humans during the picking. Instead, the picking process is controlled by a computer and automatically carried out by machines or robots.

On the one hand, these systems minimize labor costs, are less prone to errors, and work faster than humans. On the other hand, however, they come with disadvantages, too: Automated systems require high investments up front and are expensive to maintain. In addition, they are much less flexible.

Manual order picking

Manual order picking means that the warehouse worker puts together the required goods by hand. Manual systems are commonly used because they are possible to implement at lower cost and in most cases extremely flexible. Humans can adapt quickly and easily to changes in workflows, e.g., the introduction of new package sizes or new items.

Picking Processes: Advantages and Challenges

When it comes to processing an order, there are various ways in which a warehouse clerk can fulfil their task. Let’s have a look at the different picking methods and their characteristics and explore some of their advantages and disadvantages.

Pick-by-Paper

All information about the order (item type, quantity, storage location) can be found on a printed picking list. Based on this information, the packer picks the required items. They then confirm the pick, usually by checking it off on paper.

Pick-by-Paper solutions are easy to implement, and training can be carried out rather fast. All in all, their set-up is very economical as the preliminary investment costs are low. The workflows are also easily adaptable to new conditions, which makes these solutions very flexible.

As they rely on human beings, they are, however, highly error-prone. The picking process is also extremely time-consuming: For example, new orders must be printed and picked up and order data must sometimes be processed several times to get it right. Additionally, the packer cannot work hands-free. Furthermore, no real-time communication with a Warehouse Management System (WMS) is possible, which can lead to errors and wasted time.

Pick-by-Scan/Pick-by-MDE

Here, the material handler gets the picking list displayed on a mobile data entry device (MDE). With the integrated barcode scanner, the pick can be scanned and confirmed thanks to a barcode on the shelf or on the product itself.

The Pick-by-Scan method allows the picker to work with digital information, thus making analogue picking lists obsolete. Additionally, real-time communication with the Warehouse Management System (WMS) is possible. A Warehouse Management System manages, controls, and optimizes all processes in a warehouse. The system keeps track of all the inventory that is stored, from its delivery until the items leave the depository after they are picked.

This communication with the WMS greatly reduces the risk of errors and speeds up internal processes, as the Warehouse Management System can adjust the inventory in real time directly after the scan.

Still, the work requires the handler to hold a scanner, which means that they have at most one hand free. The user interface of Pick-by-Scan solutions is also often not greatly intuitive. This can lead to longer training times for new employees and cause confusion for them, which means they make more mistakes and lose more time.

Pick-by-Light

This solution requires no pick list at all, as the warehouse operative receives the information directly at his location in the warehouse: small LEDs on shelves light up to show the packer from which one the goods are to be picked. Digital displays next to the shelves provide information about the desired quantity. Afterwards, the worker confirms the removal by pressing a button on the shelf.

This approach is paperless and leaves both hands of the handler free for other tasks. Less search time also means faster picking. Additionally, the workflows are easy to learn.

Investment costs, however, are high for this approach, as Pick-by-Light solutions usually require specific infrastructural changes in the warehouse setup. This also means that adapting the workflows is often complicated, which makes them rather inflexible. Additionally, there is often no way of determining individual specifications for the picker: the light signal is displayed to all, so only one worker per aisle is possible.

Pick-by-Voice

Here, the warehouse operative wears a headset connected to a data device. The picking system sends the orders to this device, and it then proceeds to provide the packer with the necessary information about the order via speech output. They in turn also interact with the system by speaking into the headset. This way, the operator is, for example, able to confirm the removal of goods.

Pick-by-voice solutions again allow the packer to work hands-free as there is no paper list involved. The device is also linked to the Warehouse Management System in real time which can adjust the inventory directly.

Nevertheless, the time it takes to complete the picking can be higher with this approach, since article numbers or quantity must be entered by voice input. The headset also isolates the employees from each other, which makes communication more difficult.  Furthermore, working with Pick-by-Voice systems is extremely monotonous for the operators, as they have no multimedia access and there is only one way they receive the needed information. Additionally, audio input takes longer to process than visual information.  This can lead to employee dissatisfaction and a higher turnover rate.

Pick-by-Vision

With Pick-by-Vision solutions, the picking takes place with the help of smart glasses or head-mounted displays (HDM) worn by the warehouse worker. Via augmented reality technology, the operator sees the information regarding the order directly in their field of vision: Not only is the location of the article displayed, the smart glasses or HDMs also show the operator the item to be picked itself – by displaying the article number or a picture – plus the required quantity. The operator confirms the pick via scan – either with the camera that is directly integrated into the smart glasses or a scanner connected via Bluetooth, e.g., ergonomic ring or glove scanners or wearable RFID technology. The scan via camera is suited for use cases with a rather low volume of confirmation steps. When the picking intensity is high and a lot of confirmations are needed, Bluetooth scanners are usually the better choice.

This approach again allows hands-free picking. Pick-by-Vision solutions also greatly reduce training and onboarding times for pickers: Easy-to-follow step-by-step instructions provide only the information the new worker needs at the exact moment and in an intuitive visual way, which speeds up their learning process considerably. This means that the operator starts to create value almost instantly.

Additionally, there is no need for changes in the warehouse itself and seamless integration into the Warehouse Management System is the standard for most vision picking solutions as well. The picking process is also quicker: Information is generally grasped faster by visual cues and the needed instructions are shown immediately on the displays. Furthermore, the warehouse operative greatly benefits from the ergonomic wearables.