A wrong product in the box, a missed order, an incorrect quantity: picking errors may seem small, but they eat away at your margins and customer satisfaction. In this guide, you will learn where picking errors come from and what concrete measures you can take to reduce them structurally. From warehouse layout to scan verification: you will receive a practical step-by-step plan to reduce picking errors in your warehouse.
What are picking errors and why do they cost you more than you think
A picking error occurs in four ways: an employee picks the wrong product, the wrong quantity, from the wrong location, or an order line is forgotten entirely. It seems harmless, but every mistake sets a chain of extra work in motion.
The true cost of one picking error
Do the math. A picking error often leads to a return, and a return costs an average of between 8 and 15 euros in processing: packing, shipping costs, customer service, re-inspection, and sometimes writing off the product. On top of that comes the reshipment of the correct product.
However, the indirect costs outweigh the negative ones. A customer who receives the wrong product doesn't think "logistical error"; they think "unreliable webshop." That costs you a negative review, a lower chance of repeat purchases, and sometimes a complaint that becomes publicly visible. With an average order value of 50 euros and a lifetime customer value that is much higher, the damage from a single picking error is easily many times the direct costs.
When a high error rate becomes a problem
In e-commerce fulfillment, the average error rate ranges between 0,5% and 3%, depending on the product range, order complexity, and the process used. With 1.000 orders per week, 2% already means 20 erroneous orders, week after week. If you are consistently above 2%, it is time to take action. Below 1%, you are in the safe zone, but even then, optimizing is worthwhile as soon as your volume grows.
The most common causes of picking errors in the warehouse
Before implementing solutions, it is smart to understand where errors come from. Not every error has the same cause, and not every solution works for every type of error.
Human errors versus system errors
Some errors are caused by human action: fatigue, haste, inattention. But at least as often, the cause lies with the surrounding system. Consider:
- Unclear or nearly identical SKUs (the same shoe in two sizes side by side)
- Packaging that looks very similar
- A warehouse layout with long, illogical walking routes
- Manual administration without scan verification
- Insufficient training of new employees
System errors are structural: they keep recurring until you remove the cause. Human errors are incidental, but a poorly designed process makes them much more likely.
Why peak workload causes error rates to rise
During Black Friday or the month of December, you often see the error rate double or triple. The cause is a combination of factors: temporary staff unfamiliar with the layout, higher hourly picking pressure, and less time for quality control because speed is paramount. Precisely during these periods, it is smart to incorporate extra scan checks rather than eliminating them “to save time”: one missed order ultimately costs you more time than an extra scan.
Reduce picking errors by optimizing your warehouse layout
Many picking errors can be traced back to the physical layout of the warehouse. A smart layout prevents errors before they occur.
Applying ABC classification in your warehouse layout
Divide your assortment into A, B, and C products based on turnover rate. Place A products (fast movers) close to the picking stations and in spacious, well-organized bays. C products (slow movers) can be placed further away. This not only prevents unnecessary walking but also congestion and confusion around the most popular locations.
Other concrete measures:
- Never place look-alike products (same color, similar packaging) next to each other.
- Use clear, legible location labels with barcodes.
- Work with fixed picking locations per SKU instead of chaotic storage.
- Ensure a logical zone division that aligns with your order profile.
Tip: walk along a picking route with a new employee yourself. You will then immediately see where confusion arises, something that often remains invisible on paper.
Do you want to delve deeper into layout choices? Also read Successfully Setting up your warehouse for a comprehensive approach.
Picking methods that structurally reduce the risk of error
In addition to the physical layout, your picking method also determines how error-prone your process is.
Batch picking: faster, but risk of mix-ups
In batch picking, an employee collects products for multiple orders simultaneously. This is efficient for high volumes and many similar orders, but the risk of order mix-ups is greater. Without supporting technology, such as scan verification per order, the risk of incorrect assignment is highest here.
Zone picking as a solution for large assortments
With zone picking, each employee is responsible for a fixed section of the warehouse. Orders travel through the zones, and each employee picks only their own section. This works well for large assortments because employees get to know their zone inside out, which reduces the risk of errors.
Single order picking, where one employee collects one order from start to finish, is the least error-prone but also the least efficient for large volumes.
| Picking method | Speed | Susceptibility to errors | Suitable for |
|---|---|---|---|
| Single order picking | Low | Low | Small volumes, complex orders |
| Batch picking | High | High (without tech) | Large volumes, comparable orders |
| Zone picking | Intermediate | Average to low | Large assortment, multiple zones |
Would you like to compare the methods in more detail based on your order volume? Then check out comparing order picking methods.
Reducing the role of technology and scan verification in picking errors
Layout and process are the foundation, but technology is often the decisive factor in structurally reducing picking errors in your warehouse.
What a WMS specifically changes in the picking process
A warehouse management system links every pick directly to the order line in the system. Instead of relying on an employee's memory or attentiveness, a scan confirms that the correct product has been picked from the right location. Errors are detected immediately, before the package leaves the warehouse, not just when the customer files a complaint.
A WMS like Lyra WMS catches picking errors by setting a scan requirement per order line and immediately displaying an error message in the event of a mismatch between the scanned and expected product. This prevents an error from only coming to light afterwards, during the return process.
Scanning requirement: make mandatory or optional
You can set scan verification to mandatory or optional. With mandatory scanning, an employee simply cannot proceed without scanning the correct barcode, which reduces the error rate to nearly zero. It takes slightly more time per pick, but that time loss is usually less than the time spent on returns processing.
Option 1, scan requirement off: faster picking, higher risk of errors. Only to be considered for very experienced teams and low-risk products. Option 2, scan requirement on: slightly slower per pick, but the error rate often drops to below 0,5%.
In addition to barcode scanning, pick-to-light and voice picking are valuable for high volumes: the employee receives visual or spoken confirmation without having to operate the scanning device, combining speed and accuracy. Furthermore, real-time inventory control prevents employees from walking to a location where the product is no longer in stock, which can lead to incorrect substitutions. You can read more about the basics of these types of systems in what is a WMS.
Training, feedback, and work instructions as the key to fewer errors
Technology does not solve everything. Without proper training and clear instructions, the human remains the weakest link.
Ensure standardized work instructions for each picking process: how to scan, what to do in case of an error message, and how to pack a fragile product. Have new employees shadow an experienced colleague for the first few days before they start picking independently. This prevents most beginner mistakes.
Register errors, but use that data to learn, not to settle scores. A blame culture causes employees to hide errors instead of reporting them, which actually obscures your view of the real cause. Discuss errors in short, constructive feedback sessions.
Tip: Hang short, visual instruction cards at the picking location itself, not just in a handbook that no one consults during the work.
Measuring and monitoring picking errors: which KPIs really count
You can only structurally reduce picking errors if you measure them. Without numbers, you rely on gut feeling.
Pick accuracy rate: how exactly do you calculate it
You calculate the pick accuracy rate as follows:
(Number of correct picks / Total number of picks) x 100%
If you have picked 5.000 order lines and 4.950 of them were correct, your pick accuracy is 99%. That sounds high, but with large volumes, that still means 50 incorrect lines.
Go beyond the total score and keep track of:
- Error rate per employee (for targeted training)
- Error rate per product or SKU (for look-alike issues)
- Error rate per zone (for layout problems)
- Return reasons linked to picking errors, so you distinguish between picking errors and other return reasons such as wrong size or dissatisfaction
Build a weekly or monthly report that brings these figures together. This allows you to spot trends early and make adjustments before a problem becomes structural. This also aligns with a sound inventory management approach for your webshop , where accurate data likewise forms the foundation.
Step-by-step plan: how to structurally address picking errors in your warehouse
- Measure your current error rate and causes. Collect at least four weeks of data before drawing conclusions.
- Adjust layout and product placement. Separate fast and slow movers, set look-alike products apart.
- Enter scan verification. If necessary, start with a pilot in one zone before rolling out warehouse-wide.
- Train employees and standardize instructions. Provide visual instruction cards and a proper onboarding period.
- Monitor KPIs and adjust. View pick accuracy weekly and feed return data back to the shop floor.
This order was chosen deliberately: measure before adjusting, and implement structural solutions (layout, technology) before behavioral change (training). This prevents you from training people on a process that you adjust again just a month later.
Frequently asked questions
What is an acceptable error rate for picking in a warehouse?
An error rate between 0,5% and 1% is considered good performance in e-commerce fulfillment. If you consistently exceed 2% to 3%, action is required. What is acceptable depends on your industry and order complexity: a warehouse with many similar products in different sizes and colors generally accepts a slightly higher percentage than a warehouse with little variation per SKU.
How do you prevent picking errors without immediately investing in a WMS?
You can achieve a lot even without software. Ensure clear, legible location labels, use checklists for picking and packing, implement double checks for high-risk orders (for example, large quantities or expensive products), and optimize your warehouse layout by separating look-alike products. These low-tech measures significantly reduce the error rate even before you invest in technology.
What is the difference between pick accuracy and order accuracy?
Pick accuracy measures the accuracy per order line or product: for all individual picks, what percentage was correct. Order accuracy measures the accuracy per complete order: an order only counts as correct if all lines within it are correct. For example: an order with five lines, one of which is incorrect, counts as 80% correct for that order for pick accuracy, but for order accuracy, the entire order counts as incorrect. Order accuracy is therefore always stricter and provides a more realistic picture of the customer experience.
Does batch picking or single order picking help prevent errors better?
That depends on your situation. Batch picking is faster at high volumes, but without supporting technology such as scan verification per order, it is more prone to errors because products for different orders are more easily mixed up. Single order picking is slower but more organized: one employee tracks one order from start to finish, which reduces the risk of mix-ups. For large volumes, the combination of batch picking with scan verification is often the best balance between speed and accuracy.
Would you like to know how to handle this in your warehouse? Schedule a no-obligation discovery call and we'll go through it together.
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