Wave Picking Guide
The picking process is one of the most vital aspects of your warehouse operations – but it’s also one of the most complicated.
Picking involves warehouse staff having to navigate through a gigantic maze of shelving systems to find the items they need to pick, so it’s no wonder that many ecommerce businesses struggle with picking efficiency and order accuracy.
To keep your fulfilment operations running efficiently, it’s crucial to implement the right warehouse picking strategy. Wave picking is one such strategy, as it can help streamline and optimise the picking process.
In this guide, we break down the benefits of wave picking and how you can implement it for your own warehouse.
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What is wave picking?
Wave picking (also called cluster picking) is a picking strategy that involves picking multiple orders in a single trip through the warehouse storage shelves.
How does wave picking work in the warehouse?
In wave picking, an order isn’t picked as soon as it comes in. Rather, it’s usually put on hold for a period of time so that a warehouse management system (WMS) can sort it into a group. The system groups multiple orders together based on one or more factors that all those orders have in common (such as storage zone, shipping date, items, or carrier).
These groups get released for picking at certain time intervals, referred to as “waves”. For instance, picking waves may be released every half hour, or every three hours.
Each group is assigned to a picker, who will pick all those orders in one “wave”, or trip through the warehouse. Waves typically occur at periodic intervals of time, such as every half-hour.
Each group is assigned to a picker, who uses a cart or tote to pick all the items assigned to them in a single trip, instead of having to walk back and forth multiple times to pick individual items. This significantly improves picking efficiency, and can help your team meet a specific productivity goal (such as getting all orders with a particular shipping deadline fulfilled in time, or each picker fulfilling a certain number of orders per shift).
Wave picking is the strategy of choice for both small and large ecommerce operations. It’s particularly ideal for warehouses that handle large numbers of SKUs.
Wave picking vs. batch picking
Wave picking and batch picking are often mixed up, since they both involve picking multiple orders simultaneously. However, the two are slightly different.
Batch picking involves picking multiple similar orders in one trip. Those orders can be identical (i.e., they contain the exact same combination of products), or they can simply be similar (containing some of the same products).
Wave picking is a form of batch picking, just with a timeframe. Wave picking groups orders with similar features together, but releases groups of orders for picking at certain times in order to keep on a schedule.
Batch picking is highly desirable for warehouses that have to process a high volume of orders with small items that can be picked together. It wouldn’t be as convenient to pick multiple units of large SKUs at the same time, for example.
Wave picking, on the other hand, is more suitable for warehouses that have to process a high volume of orders with similar items that can be picked together.
Each picking strategy offers unique benefits depending on a brand’s needs. Instead of sticking to just one order picking method, businesses can also combine batch, wave, and zone picking to optimise their inventory retrieval process. Ideally, these picking strategies should be executed with the help of a warehouse management system to optimise picking lists and wave schedules.
6 benefits of wave picking in the warehouse
Based on the description above, you might already have some idea of how wave picking can benefit your business. Here’s a more detailed breakdown of the benefits of wave picking in the warehouse.
1. Greater warehouse efficiency and space utilisation
Wave picking minimizes the time that pickers are physically walking to and from different storage locations. That extra time can be used to pick and pack more orders or perform dozens of other tasks around the warehouse, increasing the warehouse’s overall operational efficiency.
Moreover, wave picking can also improve warehouse space utilisation. By orchestrating waves so that multiple pickers aren’t assigned to the same aisle, zone, or picking location at the same time, you reduce congestion, minimise bottlenecks, and even improve your warehouse’s safety.
2. Fast, accurate order fulfilment
Wave picking is designed to enable pickers to pick as many items as possible in a given time period. Whether they are picking multiple units of the same SKUs or picking a bunch of different SKUs in the same area, pickers typically don’t have to zigzag around the entire warehouse just for one order. This reduces travel time and speeds up the order fulfilment process.
Because a picker isn’t moving around as much, they can also pay more attention to what they’re picking and how many units they need. This significantly improves order accuracy rates as it minimizes the risk of mispicks.
“For us, one of the greatest benefits in using ShipBob’s WMS has been reducing mispicks. Before ShipBob, when we were just relying on label generation software, we didn’t have a way to validate which products were going out to customers. The label would say “pick 3 of these specific sunglasses” but really, you could have sent any type of sunglasses since there was no validation – and that happened frequently. One of the biggest reasons we went with ShipBob is the multiple checks from start to finish. The WMS makes it really hard to send out the wrong product. It still happens on rare occasions – but it happens a lot less than before. Before we implemented ShipBob’s WMS, our order accuracy rate was around 92%. Now we’re at 99.7% for order accuracy, which equates to 2,100 less mispicks a year on average.”Jourdan Davis, Operations Manager at Pit Viper
3. Fewer operational errors
Since wave picking is carried out at specific times throughout the day, warehouse managers can schedule each wave so that none of them interfere with other warehousing processes.
With a specified picking window for picking, managers can better coordinate warehousing operations. For example, managers can schedule shipping windows based on the estimated timeframe in which picking and packing will be completed. This type of planning allows for fewer mix-ups and operational errors in the warehouse.
4. Reduced overhead (cost-benefit analysis)
Picking is a huge cost centre for warehouses, so it’s important to optimise your picking strategy to keep spending in check. With wave picking helping you fulfil more orders in a short amount of time, your brand can significantly reduce your operating costs. Even if you’re spending slightly more on labour, you’re getting more out of your workers’ time if you’re exponentially increasing picking rates.
To get a better understanding of the cost savings offered by wave picking, let’s do a simple cost-benefit analysis. Say your usual picking method lets you pick 500 orders in a day, each of which is worth an average of $25, and you’re spending $2,000 per day on labour costs. In this scenario, your cost-benefit ratio would be:
Cost = $2,000
Benefit = $25 x 500 = $12,500
Cost Benefit Ratio = (12,500/2,000) = 6.25
Now imagine that you start wave picking. Because it’s a more efficient picking system, double the number of orders picked in a day. Even with a $1,000 increase in labour costs, your cost-benefit ratio is still higher than it was before:
Cost = $3,000
Benefit = $25 x 1,000 = $25,000
Cost Benefit Ratio = (25,000/3,000) = 8.33
5. Profitable customer satisfaction
Customers always want correct orders delivered quickly, so anything your brand can do behind the scenes to contribute to that outcome contributes to customer satisfaction – including picking.
Wave picking allows you to fulfil orders on time by scheduling waves so that the picking and packing processes are completed before shipping cut-off times. This allows for on-time shipping, which allows customers to receive their orders in a timely manner.
The greater levels of accuracy seen in wave picking also mean your customers are more likely to get exactly what they ordered. This not only improves satisfaction but also prevents the likelihood of returns, saving you money and adding to your profitability. Moreover, satisfied customers are more likely to come back and keep buying from you, contributing to your future profitability.
6. Next-level inventory management
In addition to improving fulfilment, wave picking can also improve your inventory management.
Wave picking allows for orders to be fulfilled more accurately, which means that there’s a lower risk of inventory errors. For example, items that were accidentally picked in error are quickly detected during consolidation and then returned to their respective storage locations.
Additionally, wave picking enables just-in-time picking, which is ideal for high-value and perishable items. This means there’s less idle time that could lead to high-value items being stolen or broken, and less time for perishables to spoil or lose freshness.
Wave picking tips and strategies for the experts
Although wave picking offers a number of benefits, you need to be strategic with execution to enjoy these benefits. Here are some tips and strategies to ensure that you get the most out of wave picking for your warehouse.
Choose the right wave picking method for your business
One of the most crucial steps is deciding on a wave picking method that works for your business. You’ll need to determine how to group orders in waves depending on factors such as your product type, warehouse size, and order volume. Some ways you can group orders in a wave include:
- By like products: This is the most common wave picking method and involves grouping products that are in the same category or that are often ordered together. Usually, the grouped products are stored in the same area of the warehouse. For example, one group may consist of makeup and skincare, which are stored near each other.
- By location: In some cases, warehouses may also plan waves so that all the products to be picked are in a specific location. That way, a picker only has to travel to one section of the warehouse.
- By shared feature: These products will share similar characteristics, such as size, shape, or even handling requirements. For example, you may schedule a wave for orders containing only small items that are easy to lift.
- By carrier: If your business partners with multiple carriers, it’s likely that you’ll have to work with different pickup times and shipping guidelines for each carrier. Grouping waves by carrier is a great way to streamline the fulfilment and shipping process in this case.
- By shipping schedules: Different shipping methods such as express shipping, group shipping, and next-day delivery will have different pickup times. If your business offers different shipping options, consider planning waves to accommodate these different shipping schedules. This is perfect if you want to prioritise orders based on delivery urgency.
- By delivery zones: Some warehouses may plan waves based on where orders are going. This is particularly useful when you’re fulfilling a large number of orders that are all getting delivered to the same area.
- By warehouse priorities: Waves can also be scheduled according to your top warehouse priorities, which may change from time to time. For example, you may want to create waves prioritising orders that contain a lot of perishables if your brand needs to move a particular lot out before it expires.
- By shift changes/workforce availability: Warehouses can schedule waves according to their workforce availability. During peak, for example, you may group waves to make the most of the available staff. You can also create picking schedules to avoid picking cycles being interrupted by a shift change (which leaves you more prone to picking errors).
Besides the above, it’s important to decide between fixed wave picking and dynamic wave picking. If you go with fixed wave picking, orders will be held for packing until the rest of the items in the wave have been picked. This allows you to maintain more structure and coordinate with other warehousing processes, although it requires more staff.
Meanwhile, dynamic wave picking allows you to send individual orders for packing as soon as they’re completed. This significantly speeds up the process and reduces your workforce needs. However, there’s less predictability in terms of order flow, which could cause disruptions or bottlenecks in other warehousing processes.
Implement your wave picking strategy (step-by-step)
Wave picking must be carefully implemented to produce optimal results. Follow these steps to execute your wave picking strategy.
Calculating optimal picking routes
Before grouping each wave, consider your warehouse layout. You’ll want to create pick lists based on optimal picking routes, and ensure that your picking staff travels seamlessly throughout the warehouse in a logical flow. This step is essential to minimise travel time and allow workers to follow an intuitive picking route that facilitates the next stage of your warehousing process.
Defining cart handling strategies
It’s also important to clearly define your cart handling strategies to improve the efficiency of picking tasks. Determine the equipment that your workers will need to complete their picking tasks and ensure that they’re properly trained on how to use it.
For smaller items, you only need a tote or a cart to transport an entire group of items. However, you may need to use forklifts for transporting items that are large and heavy. Have a proper strategy in place for how to handle different types of items so you can avoid accidents and disruptions resulting from improper handling.
Optimising pick assignments
The next step involves optimising pick assignments before they’re ready to be handed off to your picking staff. Consider factors such as the number of staff in the shift, time available, picker capacity, and traveling time to create optimal pick assignments for your workers.
This will ensure that you’re not assigning staff with more work than they can realistically handle, which could result in overexertion, burnout, accidents, mispicks, and employee dissatisfaction.
Using technology to streamline
Another essential step is to ensure that your warehouse is equipped with the necessary technology to support your wave picking process. This may involve the use of hand-held mobile scanners where workers receive a pick list and get directions to product locations as well as instructions on how to handle each item.
These scanners simplify the picking process by allowing your staff to scan each item’s barcode and confirm the pick. They can further keep track of their picks by entering the quantity on the mobile device. This significantly enhances accuracy and allows workers to efficiently complete their picking activities with minimal error.
Avoid these wave picking mistakes
If it’s your first time trying out wave picking, make sure to avoid these common pitfalls:
- Grouping vastly different orders together. The similarity of orders in a wave is the biggest driver of efficiency. If the orders in a group are too different from each other, it defeats the purpose of wave picking and isn’t nearly as time- or cost-effective.
- Scheduling shift changes that could disrupt a picking cycle. This means that the wave is interrupted, which leaves more room for error.
- Failing to consider delivery commitments. If your business offers priority shipping options, this mistake could delay urgent orders.
Measure your wave picking success
Once your wave picking strategy has been implemented, make sure to closely monitor how it impacts your warehouse performance. That way, you’ll know if wave picking is the best strategy for your brand, or if a different solution would be a better fit.
You’ll need to keep track of relevant warehouse KPIs that involve your picking process, such as picking efficiency, picking cycle time, and order picking accuracy. You should also monitor its impact on other aspects of your performance, such as order fulfilment costs.
Optimise wave picking with a warehouse management system (WMS)
One of the best ways to optimise your wave picking and avoid the mistakes above is by using a warehouse management system (WMS).
The right WMS will automatically group orders for each wave based on a number of logistic criteria. It factors in the individual capacity and workload of pickers to create balanced pick assignments, so that tasks are completed on time without putting too much strain on your picking staff.
Moreover, a WMS can automatically monitor your warehousing operations in real time to coordinate other warehousing with your picking cycles. This helps you quickly detect any complications, disruptions, or bottlenecks so you can respond in a timely manner and avoid unscheduled downtime.
ShipBob’s WMS activates lightning-quick warehouse management and order fulfilment
As a global ecommerce enablement platform, picking and packing orders is ShipBob’s bread and butter.
ShipBob’s proprietary WMS powers dozens of our fulfilment centers across the world, and your business can even implement that same technology in your own warehouse to automate and optimise picking – and warehouse operations in general.
ShipBob’s WMS supports flexible picking options including batch, auto-cluster, custom cluster, and single-order picking. Instead of relying on a one-size-fits-all method, we help you analyse the order picking methods that work best for your warehouse depending on your unique needs. With ShipBob’s WMS, you can generate pick lists for each wave based on optimal picking routes to reduce travel time. This significantly enhances your picking efficiency and helps you get the most out of your wave picking strategy. Brands like Infuze Hydration were able to increase their fulfilment speed by 130% while reducing their picking error rate by 35% in a 12k square foot warehouse.
“Prior to ShipBob, we’d ship 300 orders/day. On that first night, we shipped 700 orders in the same timeframe. That speed is so valuable and so seamless.”Rick Corbridge, COO at Infuze Hydration
The system also provides you with real-time visibility into your warehouse so you can easily identify any issues or backlogs that could disrupt your picking cycle. This allows you to quickly resolve these issues before they spiral, and keep your warehouse operations running at peak efficiency.
For more information on how ShipBob’s WMS can help you perfect your picking strategy, click on the button below.
Wave picking FAQs
Below are answers to common questions about wave picking.
What is cluster picking?
Cluster picking is another term for wave picking. Both refer to the process of grouping multiple orders that all share a common feature, and picking them simultaneously at certain times or intervals of time to increase efficiency.
What is zone picking?
Zone picking is the process of assigning pickers to pick items from specific physical areas in the warehouse.
How can wave picking reduce labour costs?
Wave picking helps a merchant accurately estimate labour needs based on picking windows and scheduled waves. This in turn helps them plan staffing levels accordingly, and reduce labour costs.
Does ShipBob use wave picking in its order fulfilment process?
Yes. ShipBob leverages a variety of picking methodologies to ensure efficient fulfilment, including including batch, auto-cluster, custom cluster, and single-order picking.
What is the future of wave picking automation?
The future of wave picking automation will involve increased adoption of warehouse management systems and robotics to streamline picking while minimising human travel time and labour.