May 19, 2023
Order picking – definition and methods
Order picking is considered a basic warehouse operation. Therefore, its quality is extremely important when warehouses are looking for ways to optimize the entire process. Depending on the type of warehouse and its needs, there is one of three methods of picking goods most often used, with more or less human involvement.
Order picking is recognized as the most time-consuming and expensive internal logistics activity. This is due to the fact that there are many needs to be fulfilled. During one day, the warehouse prepares orders of the same type of goods for one customer, then starts working with many types of loads that differ in shape, size and weight and are for many customers. In the other case, a crucial element is the additional implementation of the milk run method, which, without the use of the right tools, takes up further valuable minutes and, if developed incorrectly, even hours of daily work. How do model warehouses deal with this? They use knowledge and technology.
Order picking – definition
The definition of picking (commissioning or order picking) says it is the activity of collecting and combining a number of loads to create an order for one or more customers. In practice, it refers to several levels of daily work and every modern warehouse seeks so-called optimal picking, which reduces time and, therefore, costs to a minimum.
Upon analysing the flow of goods in the warehouse and its infrastructure, it is possible to choose between manual, automatic and semi-automatic picking. The first one refers to operations that are carried out in a fully manual manner. How is picking done in an automated warehouse? Automatic picking takes place when the entire operation is performed by machines. Today, the most common method is semi-automatic, where warehouse workers use forklifts, for example.
In addition, order picking can be divided into single-stage and multi-stage picking. Single-stage picking is carried out at a specific storage location. Multi-stage picking refers to a situation where the process takes place at several stations arranged for this purpose.
Thus, the most important factor is the analysis of the flow and movement of goods in the warehouse itself, the technical equipment and the designation of packing and release zones. It is possible to apply different picking systems in each warehouse, regardless of whether you work with shelf, pallet, flow or cart-operated racks or in a fully automated warehouse operated by a stacker crane. Well-designed aisles and correctly positioned goods are more than half the battle, especially for non-automated projects. The three most common picking methods are: goods-to-man, man-to-goods and mixed method.
If the warehouse does not make use of modern technology, this method allows the order to be prepared by the person responsible. Basically, it involves walking around the warehouse and selecting goods from a pre-prepared list, known as Pick and pack. The use of Pick by light (PTL) illumination technology combined with the WMS is a significant improvement to this process. Next to each flow rack there is a screen showing where the goods are located and how many units need to be picked. When the activity is finished, the storekeeper marks the completion of the task and the information is sent to our WMS. Once the order is picked, a lamp located on the other side of the rack lights up. The operator takes the products collected in the boxes, confirms their receipt and prepares the goods for shipment.
When the scope of the assortment is small, the Put by light method is used, which allows consolidation at the rack. This eliminates an extra sorting step in the previous method. More importantly, this system allows several people to work at the same time. The system eliminates costly mistakes in the selection of goods, especially in group picking, where several orders are processed within a single picking order.
The advantages of the man-to-goods method include high picking efficiency and low investment costs. On the other hand, it requires longer distances to be travelled, which is also related to the time required for the process. There is also the risk of making a costly mistake.
How does goods-to-man picking work?
Unlike the dynamic man-to-goods method, the goods-to-man one is a static system. A worker responsible for commissioning remains at the picking location, and the goods are delivered to him/her through the means of transport available at the warehouse. This method is most commonly used at automated warehouses, where goods are stored in automated container warehouses and delivered to the order picking location. The operator takes items from the containers, and the system, which is connected to the WMS, moves the containers back to the rack. Using this system reduces the number of errors and accidents in the warehouse as well as shortens the lead time.
The difference between the man-to-goods and the goods-to-man systems is mainly in efficiency measured in lead time, the costs incurred due to errors and the investment costs related to the implementation of an automated solution.
The two systems can be mixed together, depending on the degree of order variety and its frequency. For orders with a small variety of goods, man-to-goods is considered a more cost-effective method.
The advantages of this method are: high efficiency, related to lead time, low error rate, wide range of article selection and the possibility of designing an optimal workstation. Disadvantages include high investment costs, risk of stopping processes when the system fails, or less work flexibility for the commissioner.
WMS system to support commissioning
With a large number of orders, the traditional paper picking list is becoming a thing of the past and software such as the Warehouse Management System is becoming indispensable. This allows us to speed up the commissioning process considerably by combining it with, e.g., a radio terminal. Thanks to the WMS, we can also take advantage of the multipicking model, which allows the simultaneous collection of goods for multiple orders. The number of orders can be unlimited, depending mainly on the specifics of the warehouse. For example, individual orders can be marked with the colour of the baskets. It is also possible to set the rules for this method, such as the order of selection of racks. The system itself is primarily designed for inventory control. Its high level of integration also speeds up commissioning. That is why warehouses often decide to purchase it.
The final stage of picking is to prepare the pallets for the carrier. Some WMS systems offer simplified solutions that simulate the process of optimal distribution of goods on a pallet, however, a large part of the warehouse market still relies on the experience of the storekeeper. Systems that support the pallet stacking sequence process have two advantages over the goods-to-man method – time and safety. A load that has been improperly placed on a pallet can be partially damaged. Bearing in mind that the responsibility for the load usually lies with the shipper, it is worth taking a look at the statistics of damage resulting from this.
Goodloading – palletizing software
This is where the latest version of Goodloading comes in with help, offering a palletization module. By using the planner in the online version or integrated with WMS/ ERP or TMS, we get a suggestion for the optimal distribution of the load on the pallet, after which we can place the pallet with the goods already inside the truck or container.
The application is used by both fully automated and manual warehouses, saving time in the safe preparation of pallets and their management in the chosen cargo space.