Warehouse Picking Accuracy: 5 Advanced Strategy Ideas

In the fast-paced world of logistics, mastering warehouse picking accuracy isn’t just an operational goal. It’s an indirect measure of associate morale, best practice compliance, as well as overall operating success.

improve warehouse picking accuracy

Introduction

Imagine a world where orders flow seamlessly from shelf to shipment, where every pick is precise, and customer satisfaction is not just met but exceeded. This is not a distant dream but a tangible reality that innovative strategies and cutting-edge technologies are bringing within our reach. 

In this comprehensive guide, we will take a deep dive into the arsenal of tools and tactics that are transforming warehouse operations, ensuring that you’re not just keeping pace but setting the pace in the relentless race for efficiency and excellence. 

Buckle up as we explore the advanced strategies and future-ready innovations that will elevate your warehouse picking accuracy to unparalleled heights, making it your ultimate competitive advantage.

Pro Tip: Early in my career, I managed a warehouse that was struggling with order accuracy. Our target was 99.8%, but we were stuck at 98.5%. At first, motivating the team was difficult. 98.5% might seem like a high score, but is a 98.5% success rate acceptable in a hospital delivery room? This analogy resonated with the team. We then implemented real-time error feedback communication and tracking, and within 6 weeks, our accuracy improved to 99.2%. This experience highlighted the importance of clear goals and a focus on continuous improvement.

Quality Metrics: Internal vs. External

Internal Quality is calculated based on data collected in-house. These data collection methods include random audits, system-driven audits, size, weight, and image-based audits, QA/QC audits, and load audits, to mention a few. Let’s review each type.
 
  • Random Audits: Orders (cartons or cases)* are pulled randomly from the conveyor between the picking and packing areas.
  • System-Driven Audits: Your WMS system directs cases to a QA/QC line (divert) based on pre-determined criteria. For example, new pickers could be audited more than tenured pickers. Likewise, consistently accurate pickers may not need to be audited at all.
  • Size-Based Audits: Your conveyable cases are passed through a hologram that scans the item’s length, width, and height and diverts items that do not meet the required tolerance (also configurable) to a reject line. Tolerances can be percentage-based or dimension-based.
  • Weight-Based Audits: Your WMS system calculates the weight of a carton or case as it passes (conveys) over a scale and diverts deviations based on your pre-configured settings (percent or dimension). I recommend starting with +/- 1 inch.
  • Image-Based Audits: Your WMS system knows what the cases should look like based on your initial product setup and diverts deviations.
  • Load Audits: These are typically used for retail store shipments, and every item shipped across all pallets is audited. It’s a 100% audit.

*Note: Cartons are considered corrugated boxes or totes picked into where cases are products shipped with no external packaging.

External Quality is typically calculated weekly and captures all errors customers report. These errors include the wrong quantity shipped within a carton (shipped 2 vs. 3), missing item within a carton (shipped 0 vs. 1), wrong item shipped within a carton (pencil vs. pen), and wrong case shipped (desk vs. chair). This metric does not include missing cartons or cases as they are calculated under the Cargo Loss metric (more on this metric later).

Replicating External Quality via Internal Auditing

 

To successfully replicate External Quality, you must internally audit shipments from all warehouse areas (full pallet picks, bulk items including non-conveyable, full case products including case packs greater than one, and unit or each picks). 

When these values do not match, you must review your audit criteria and sample sizes and adjust accordingly. For example, if you see more unit errors externally than internally, you need to increase your percentage of internal carton auditing.

Note: Additional areas that should be audited for quality include inbound receipts and quantities, pallet putaway, case putaway, replenishment case and pallet, dock to stock, and any value-added areas. Do NOT overlook these audits.

inventory management inventory replenishment metrics, fulfill customer orders

Calculating Facility Picking Accuracy

Before we discuss strategies and opportunities to improve your picking accuracy, we first need to discuss how to calculate this KPI.

Internal Quality

The calculations for determining Internal Quality are as follows:

Case Picks: Total correct cases picked / Total cases picked

Unit Picks: Total correct units picked / Total units picked

It is recommended to calculate these daily. If you can publish this data before noon the following day, you are doing well. It’s much easier to remember what just happened, versus what happened a week ago.

External Quality

The calculations for determining External Quality (calculated every week) are as follows:

Total Orders Shipped Accurately / Total Orders Shipped

When calculating the external quality, we recommend using orders. Either the order is correct or it’s not, regardless of the number of errors on the order. 

Remember that this value does NOT include missing orders or missing shippable cartons or cases on that order. These could have been lost in transit, lost in customs, etc. and do not represent the accuracy of warehouse picking.

Calculating Individual Picking Accuracy

There are several ways to calculate an operation quality metric. Some operations try to use sales numbers, which have zero meaning to warehouse workers. They should not be required to know the product costs or dollar value so don’t use sales. 

You want to use the number of stops or locations an associate visits. There are only a few reasons why orders have quality issues. They are:

  • Wrong Item: You travel to the pick face and either pick from another location or pick the wrong product from the right location (mis-stocked item).
  • Wrong Quantity: You travel to the pick face and pick the right item, but the wrong quantity. You can’t count, OR there is a unit of measure discrepancy (more on later).
  • Damaged: The picked item will not satisfy the customer’s needs. This may be due to presentation (your resellers can’t resell it) or actual product damage.
  • Missing Item: One of the required SKUs or products from that order is not present – for whatever reason (box fell off the conveyor, someone took it out to reorganize, etc.)

We will get to the accountability conversation further in the blog, but for now, let’s discuss how to calculate:

Internal Metrics

There are a few ways to determine the denominator for your quality equation (what you will divide your success rate by). Most companies use the total units picked as the denominator for the entire operation. 

Note: This is not the case with individual picker quality calculations. If you cannot easily get that number from a data standpoint, you must figure it out with your IT team or use lines.

Some companies use total lines. It depends on the types of picking within the operation. So, if you are unsure, use total units as the denominator. That means you will also use the correct number of units picked for the numerator. The formula looks like this:

Total Quality = Total number of units accurately picked / Total number of units picked

Pro Tip: Do not attempt to calculate quality using some formula to convert units to cases where you are picking cases with multiple inners. Sometimes there are 2 units/case, other times there are 500 units/case. You must count each case as one unit picked, regardless of how many units are in that case. It’s one touch, one mistake. Also, do not include ‘cost’ in the picking error unless you require your pickers to memorize SKU pricing.

Calculating External Quality: The Perfect Order

In the world of warehouse quality, there’s no room for gray areas. The ultimate goal is the Perfect Order: an order that is delivered to the customer on time, complete, and undamaged. Every aspect of warehouse operation contributes to achieving this ideal, but measuring external quality requires a specific focus. Here’s how to calculate it and use the data to improve continuously.

The Perfect Order Metric

No single metric perfectly captures the essence of a Perfect Order. However, the industry standard often uses a combination of three key measures:

  1. Fill Rate: The percentage of ordered items that are shipped without backorders.
  2. On-Time Delivery: The percentage of orders delivered within the promised timeframe.
  3. Order Accuracy: The percentage of orders picked, packed, and shipped without errors.

Calculating External Quality

To calculate your External Quality score, you can use a weighted average formula that considers the relative importance of each factor for your business. Here’s a sample formula:

External Quality = (Fill Rate Weight * Fill Rate) + (On-Time Delivery Weight * On-Time Delivery) + (Order Accuracy Weight * Order Accuracy)

Optimizing External Quality

The sections you’ve outlined in your blog (Analyze and Optimize Product Velocity, Strategic Inventory Organization, Technology Integration in Picking Processes, and Advanced Inventory Management Practices) all play a crucial role in improving your External Quality score.

  • Data-driven stocking: Knowing exactly how fast products move allows you to maintain optimal stock levels, reducing the risk of stockouts that impact fill rates.
  • Strategic inventory organization: Efficient storage solutions minimize picking errors and expedite order fulfillment, improving accuracy and on-time delivery.
  • Picking technology: Automation and AI can optimize picking routes, minimize human error, and increase speed and accuracy.
  • Real-time inventory tracking: Accurate inventory data ensures you fulfill orders correctly and identify potential stockouts to maintain fill rates.
  • The Internet of Things (IoT): Sensors and connected devices can track inventory movement in real-time, providing valuable data for optimizing warehouse operations.

Calculating and analyzing your External Quality score can provide valuable insights into the effectiveness of your warehouse operation. Implementing the strategies outlined in this section can help you continuously improve your processes, minimize errors, and achieve the ultimate goal: a constant stream of Perfect Orders.

the perfect order

Operational Excellence in Picking: Picking Perfection

The picking process is the heart of order fulfillment. Optimizing this stage is crucial for achieving high External Quality scores. Here’s how to achieve operational excellence in picking:

Internal Auditing

We discussed internal auditing above. To take advantage of this process, provide feedback as close to real-time as possible. You want to do this for two reasons:
 

First, the pick location could have been stocked incorrectly. While the selector should have caught the error via an SKU validation or barcode scan on the product, in some systems, you scan the location and pick the product. 

By catching mis-stocks, you not only avoid picking the item incorrectly again, but you can also track down who mis-stocked the item.

 
Second, if you are a picker and get approached by an auditor, you are more likely to pay closer attention to your picking accuracy. Maybe you forgot your glasses and can’t read the RF screen or are distracted by something outside of work. 
You can reduce my picks by communicating this to the selector in real time. On a personal note, when I got caught mis-picking an item, you can be damn certain I was more careful picking.

Posting Results

Posting the previous day’s results on a board near the picking area will grab everyone’s attention. And if you don’t want to use names, at least post results with their employee ID number. 
 
Most accountability programs are based on a weekly percentage of mis-picks., This information will force pickers to pay more attention when they accumulate errors early in the week.

Pro Tip: Do not confuse the number of errors with the percentage of errors. Several associates have 7 or 8 mis-picks within a week, which upset me until I realized they were picking twice as many orders as the others. The percent is the percent, so don’t judge someone before determining all the facts.

Case Picking Errors

For associates mis-picking full cases of product, which typically get caught in shipping, ask them to get the wrong product, remove the labels, restock the product, and then pick the right product. This may sound harsh, but it ensures that the case picker follows the best practices when throwing cases.
management of warehouse

Conclusion: Enhancing Warehouse Picking Accuracy

In the complex ballet of warehouse operations, achieving exceptional picking accuracy is not merely a goal but a continuous journey. This objective demands precise execution and the agility to adapt swiftly to the ever-changing rhythms of demand and technology.

Throughout this exploration, we have delved into everything from basic strategies to the cutting edge of technological advancements, revealing the multiple layers that form a high-performing, accuracy-focused warehouse environment.

The pursuit of unparalleled picking accuracy is an ongoing process driven by the rapid evolution of technology and the relentless improvement of operational methodologies. 

As we find ourselves at the forefront of this evolutionary wave, it is evident that the future of warehouse operations extends beyond merely minimizing errors—redefining efficiency standards and elevating customer satisfaction to new heights.

Adopting these advanced strategies and innovations represents more than just an upgrade in operations; it signifies a commitment to excellence and a bold statement that your warehouse is not merely keeping pace but setting the pace in a competitive field.

The road ahead is abundant, with possibilities for enhancement and optimization. The critical question now is not whether you can afford to embark on this path but can afford to overlook it.


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