Picking: what is the ideal model for your operation?
Understand the importance of picking and the gains generated by choosing the modality that best meets the specifics of your warehouse
The separation or preparation of applications, known as picking, is conceived as one of the most important and costly processes within the warehouse. To get an idea of its significance, studies show that picking consumes around 60% of the costs of an operation. Its high cost comes from the particularity of being a process that usually involves many people and equipment, and the displacement factor also has a significant impact (see the 7 most common problems in picking). In other words, we can say that the high number of movements in the DC and the long distances traveled can mean loss of money. How can this problem be solved?By defining the right picking strategies for your business.
Much of the picking process concerns the displacement of operators. Of course, a proper layout and the correct use of storage structures and equipment have an important impact, but they are not enough. Implementing the optimal picking modalities for your operation through technology makes all the difference.
In traditional warehouses, especially those that still use manual processes (with paper lists, clipboards etc.), one of the major difficulties is optimizing the separation process. Among the challenges faced are: defining the best position of the products on the DC (layout and balance of the lines), organizing the orders and their priority orders, calling the right operators to perform the separation tasks and reducing the movements.
Developing a strategy that addresses all these factors is not easy. That’s why the primary solution to be adopted is to rely on the support of technology. With WMS (Warehouse Management Software), all these points are covered, as the system has algorithms and functionalities that will suggest the best positions, determine the flow of inventory movements, group tasks for better use of labor and, finally, optimize company resources (people, equipment and area).
In addition to investing in technology, it is essential to use the most appropriate picking modalities for your business. Defining the ideal model for the operation depends on a number of factors, such as:
- Separation units (if orders are separated into pallets, boxes, fractions, by weight etc.)
- Amount of orders processed in the day
- Quantity and diversity of SKUs in the warehouse
- Estimated time for order separation
- Types of products stored (their shape, level of fragility etc.)
- Ease or difficulty in unitizing loads
- Warehouse dimensions and operational layout
- Inventory volume
- Seasonality in sales
This means that no picking modality is better than another, but there is one that will bring the best results for a certain type of business. Furthermore, with the aid of automated systems, the separation process can become even faster and using less labor, and in this case, there are also several modalities that need to be evaluated (pick-to-light, goods to person, and voice picking, among others).
Why choose the ideal picking modality for your business?
The choice of the most appropriate picking modalities for the operation does not mean only cost reduction and higher separation speed. Other direct and indirect benefits achieved are:
- Delivery speed (which directly affects customer satisfaction)
- Increased DC productivity (if orders are separated faster, this means more demands can be met in one day)
- Reduction of errors (such as missing or left-over items and exchanged products)
By having a system that does all the picking management, such as the WMS, it is possible to add even more gains, such as:
- Automatic picking replacement;
- Dynamic balancing of separation lines;
- Scaling the number of picking positions of the product according to turnover or ABC curve;
- Significant increase in inventory accuracy as the system coordinates tasks, tracks and records all movements made;
Real-time operation monitoring and bottleneck correction, from the dashboards and KPIs offered by the system (Visual Management).
As already dealt with in this text, each picking modality aims to meet a different context, aiming at increased productivity, as well as cost reduction. The following are the most common models:
In this picking model, each operator meets a single request at a time, so the chance of errors is lower, as only one person is responsible for the entire process. On the other hand, more time is spent, as the employee will have to go through a large part of the DC to separate the order.
For this picking model to work well, the warehouse layout must be structured taking into account the turnover of the products, that is, items that have a higher output need to occupy positions closer to shipping. And to facilitate the movement of the operator in the warehouse, they can use a cart or any other equipment that speeds up circulation in the DC.
This model can work well for warehouses that meet few orders, but with a high volume of items in each of them. Remember that the employee responsible for separating a particular request can only assume another one when they complete the separation order.
Because DC movements correspond to much of the separation costs, one way created to reduce these displacements is batch picking. This separation modality is based on the grouping of orders for the decrease of access to inventory, allowing that in each route it is possible to collect more units, thereby meeting more than one order.
Basically, batch picking works as follows: each operator collects the goods related to a group of orders in a single displacement, that is, the employee goes to the position of an item and, instead of taking the quantity requested in a single order, they collect a larger number, contemplating other orders that also demanded those goods. Subsequently, the items collected in a grouped manner are separated according to each order and destination, usually in the verification process (hive / put to wall).
Batch picking depends on technologies that group orders and then separate them. This picking modality is recommended for operations with very fractional items (e.g. e-commerce) as it decreases the number of volumes in the separation lines as fewer individual orders are required to be separated.
The gains provided by this picking modality are numerous, starting with the significant increase in productivity and decrease in labor (headcount). However, it is necessary to rely on an efficient management system for the automatic grouping and picking queue, the correct direction for the separation (multi order picking) and, finally, the verification and split in the hive (put to wall) according to each recipient.
See how Drogaria Onofre increased productivity by 60% with batch picking.Access the case study.
This type of picking works similarly to a production line. The warehouse is divided into zones (sectors) and each operator is responsible for separating into one area. The employee only collects the products from that delimited zone and passes the order to the next zone, where more items may be included (or not) until the order is complete. Conveyors and shelves close to the operator are usually used to avoid displacement and speed up the process. Zone picking works well in DCs that have a large amount of SKUs, high sales volume and quantity of items per order from medium to low.
Wave picking is a mixture of zone picking and batch picking. A wave is generated in the DC with the grouping of several orders (depending on the carrier, route or region of delivery) and the operators, positioned in their zone, collect the products that are allocated in that sector. All collections take place at the same time. Then the goods go to the consolidation area where a second separation takes place, this time to create the individual orders.
This picking modality is recommended for DCs that have a high number of SKUs and quantity of items per order from medium to high (medium-high ticket). Wave picking is widely used in warehouses where the stock is in cold, chilled or frozen chambers (e.g. refrigerators), that is, in severe conditions where the separator needs to collect the goods in the shortest time.
Bulk picking consists of the separation, whenever possible, of closed volumes (boxes or packages from industry), in order not to cause a shortage in the picking areas of fractional products (units) when there are orders with large quantities.
Imagine that, in one order, 180 units of the same item were requested. If the picking position of this product holds up to 100 units, to separate this order, two replacements would be required. Knowing that the industry packaging contains 90 units, with bulk picking, the system directs the separation to the packaging/closed boxes area. Complementing this strategy, many companies use specific areas for these volumes (reservation address/fixed address).
Another practical example would be the following: Suppose three orders are planned in different shipments (different vehicles) and have a common product. If each order contains 5 boxes of this item, and 15 boxes form a pallet stored in the DC, then instead of individually separating each order, generating several movements in the warehouse, the system groups the tasks and generates a single collection task of that pallet. As soon as the pallet is collected, it is taken to a shipping dock area and there each volume is placed on its delivery.
We can say, therefore, that bulk picking avoids repetitive efforts, generating a great saving not only of time, but also of DC resources (people and equipment). In addition, it benefits the replacement process, which will also be performed less often, but replacing a larger number of items. Thus, it is an ideal picking modality for businesses that receive orders with large quantities of the same product.
It is not always possible to keep all products in the easily accessible regions on the DC, which do not depend on forklift and, when it is necessary to allocate them in higher positions, many managers are afraid of productivity and the high cost of picking, as it becomes necessary to use equipment (forklifts and elevators). In addition, it is important to remember that there is usually competition for the resource, given the various movements in the DC, and the equipment requires maintenance, that is, it is not always available 24 hours.
An efficient solution for dealing with the picking of products in high positions and optimizing the use of equipment is two-step picking. The principle of this picking modality is simple: when separation requires forklifts or elevators, order volumes are grouped. Thus, all products allocated in high positions are collected in a single task (path traveled), and then positioned in a specific area on the floor for further separation by another warehouse team. Thus, vertical movements of equipment are reduced and picking on the floor becomes faster, reducing costs, and increasing productivity.
Pick and confirm / Picking-by-scan
The picking with confirmation is performed with the use of radio frequency (RF) collectors, which collaborate a lot so that there are no separation errors, as the separation is done by reading the barcode (GTIN, UPC, EAN, Databar, ITF-4, GS1-128, etc.) of both the product and the position. In addition, Pick and confirm the work of the operators is registered and, using the record, the system is able to generate performance indicators both individual and for the line (productivity), with the traceability of all tasks and movements (safety), without the use of paper.
Another benefit of picking with confirmation is the possibility of doing the verification by sampling. As the separation requires reading the barcode of all collected products, it is ensured that the items have been separated correctly, thus dispensing with a full verification at the time of checkout.This strategy allows a considerable reduction of labor in the operation. (See here how Drogaria Onofre decreased the headcount by 40% with pick and confirm).
Goods to Person Picking
Goods to Person Picking is a modern order separation method. The product is moved directly to the operator through machines (such as OSR Shuttle®, Carousel Systems and others) that store the items and receive WMS commands when an order arrives in the warehouse. With this integration between the software and the automation system, there is an increase in the efficiency and accuracy of the separation process, as the operator does not need to move: the product is sent to them. In addition, there is reduced effort, greater security (the product remains inside the machine without access by people) and also reduced storage space. Goods to Person Picking is recommended for medium and low turnover items and when there is little space.
Another form of automation for Goods to Person Picking is the use of robots. Watch the video showing an Amazon Fulfillment Center that uses robots to separate orders:
Also watch the video from Drogaria Onofre that deployed Goods to Person Picking with OSR Shuttle KNAPP®:
Companies that seek to have low inventory levels adhere to the cross-docking model, a logistics technique derived from just-in-time management, which determines that products and raw materials are available in stock from the moment they are needed.
In practice, cross-docking consists of the transfer or movement of products from the receiving docks directly to the shipping docks, as they are goods that already have demands for exit. Thus, in addition to maintaining a low level of inventory in the DC (invested capital), no time, labor or space is spent storing products with immediate shipment. Stores such as Mobly, Walmart, Americanas and Submarino already practice cross-docking on different scales.
The benefits of cross-docking are:
- Reduction of product handling, as they will not be stored and subsequently separated;
- Reduction of delivery time to the customer, because no time is spent preparing orders;
- Reduction of working capital, because purchases are only executed when there is a sales plan;
- Reduction of logistical costs as there are no costs for labor, equipment and storage area;
- Zero inventory, that is, concerns about stopped inventory, lack of product in stock (stockout) and also demand forecasting are eliminated.
In order for crossdocking to generate the desired results, it is necessary that the operation is very well synchronized, that is, perfectly following just in time.
Which modality to choose?
The picking modality to be adopted depends on numerous factors. Choosing the ideal model and its implementation will decisively influence your business, both in financial results and in the satisfaction of your customer.
As mentioned earlier, in refrigerated warehouses probably wave picking is the most appropriate for cold rooms, as the operator should spend the shortest possible time exposed to low temperatures. In a completely opposite case, such as an e-commerce operation, batch picking with the use of hives is a good strategy due to the high degree of fractioning. And, to ensure assertiveness in deliveries, the use of RF collectors during separation is highly recommended.
How the implementation takes place
Once the modality to be adopted is defined, how can it be implemented? There are numerous means for this and we can mention the following:
- Manual picking
- RF picking
- Voice picking
- Automatic systems
Factors such as demand, cost and quality of labor, available space and others should be considered. It is known, for example, that pick-to-light enables performance many times higher than radio frequency. But in return, the accuracy of the latter is far superior.
Typically, a distribution center adopts multiple picking modalities in order to achieve the highest possible efficiency. Delage has successful cases in which, in the same operation with WMS Rx there is also picking in waves, batches, with confirmation, in two stages and others, all supported by radio frequency, pick-to-light, shuttles, AFrames etc.
Optimization: what your warehouse needs for picking to work well
A number of additional features are critical and decisive. Picking itself is the end of a chain of mutually dependent actions. There is no point in having the ideal picking in principle if the goods are not in place and in the correct quantity, involving as few movements as possible. Among the important requirements for efficient separation, we can highlight the following:
- Line balancing
- Dynamic addressing
- Cubic volume
- Count Back
- Call active
- Visual Management
One of the points that deserve special attention is the balancing of picking lines. Balancing is understood not only the determination of the location of products at the various addresses of picking stations, but also the policy of replenishing these addresses.
It is critical that you have a WMS that allows not only periodic balancing, but also Visual Management, that is, the availability of real-time operation information, using KPIs that help in the early identification of failures and their correction. As a result, managers are able to work on the impact of unexpected demand variations, such as those that occur with products that come from a long period of chronic absence, climate change, and promotional campaigns.
Particularly in picking, Visual Management is critical. It is necessary to bear in mind that a distribution center functions as a production line. In order for it to be effectively efficient, it is important that all its links are operating as planned. All it takes is one of them to operate, for example, at 50% of what was predicted, and the result will probably also be 50%.
WMS and the flexibility required for high performance
WMS plays a determining role not only in its current needs. It should allow your operation to evolve constantly, adopting and modifying new methodologies as your business requires it. We live in a constantly changing environment, so your company needs to rely on a flexible system that is able to adapt to all the optimizations you make in your operation.
If at first you operate with products of certain characteristics and demand, tomorrow new products may be adopted, as well as demand radically changes. New methodologies and tools are likely to be adopted. Considering a company with multiple distribution centers, it is normal that different picking modalities and tools are adopted in each of them. A DC with an operational demand n times higher than another, or even with very different leasing and labor costs, will certainly implement a distinct model.
In situations like this, a robust and flexible WMS makes a difference in the business, allowing the manager to manage a complex environment in a simple and safe way, always in search of its main objectives: growth and profit.
KPIs: what can’t be measured, can’t be improved
There is a maxim about the importance of KPIs: what is not measured cannot be improved. Without a reference, your team will waste time, making unnecessary movements, in an unwanted sequence, leading to unproductivity.
Some examples of important KPIs for a picking operation:
- Time from receiving to pick location
- Inventory Accuracy
- Picking Time
- Perfect Order
- OTIF – On Time In Full
- Cost per line item shipped
It is essential that the system relies on these metrics and their availability in real time so that the manager can closely monitor the entire picking performance, thereby ensuring high productivity and the correct execution of all tasks.
Mobility: agile and efficient management
Today there are already technologies that enable the generation of picking information through mobile devices, whether tablets or smartphones, allowing the manager to monitor its operation from wherever they are. These devices are essential to perform several critical operations, such as count-back at the time of picking or inventory movement.
Imagine the area leaders and DC managers accompanying the entire operation on tablets – without the need to go to their desks and computers for information. With preventative alerts being sent directly to their supervisors’ devices, they can anticipate the occurrence of a failure, move quickly to the location where the problem happened, and act immediately to correct it. Sounds perfect, doesn’t it? The good news is that this facility already exists and is adopted by major Supply Chain leaders. With mobility, not only picking benefits but also the other processes that happen in the warehouse, allowing the ideal monitoring for the flow of the order to occur in an agile and efficient manner.
Finally, we have redeemed and listed some important tips for you to be successful in the implementation of the most appropriate picking model(s) for your operation. Check it out:
- Addresses your warehouse:
- Identify the areas of best access;
- Define the best routes to take;
- Configure storage and permission rules;
- Determine the inventory rotation sequence from input to output.
- Be careful during receiving:
- Carry out stringent verification of the products;
- Record important data, such as batch, quantity per box, and expiry date, among others;
- Deal with discrepancies and malfunctions in the correct way;
- And lastly, prepare the goods always thinking about how they will exit.
- Store with exit in mind:
- Use tools that suggest the best positions for the products with the highest turnover;
- Keep track of movements in the system;
- Constantly audit the work of those who move inventory.
- Keep your separation line balanced:
- Place the products with the highest turnover in the best positions (ABC curve);
- Periodically review the product curve;
- Have tools that allow you to quickly adapt to changes in product demand.
- Invest in technology:
- Automate manual processes;
- Have a system that directs team work;
- Monitor daily the performance indicators provided by the system;
- Rely on a system that warns you when to act (Visual Management, notifications)
- Choose a company as flexible and agile as yours.
Counting on the right technology supplier, who offers you all the facilities to deploy the most suitable picking for your business, besides allowing you to follow the process in real time, your company has everything to leverage performance in separation and, consequently, in order fulfillment.
To learn about key picking issues and how to solve them, read the article on our blog.
If you want to learn more about how WMS Delage Rx can enhance picking in your operation, click here.