warehouse insider
Many Distribution Centers (DCs) and warehouses store inventory directly at the case level rather than as pallets. This is more common when a manufacturer or brand has thousands or even tens of thousands of SKUs in the DC, and items are being picked directly from every storage location. In such situations, cases (or cartons) are stored directly on shelves, with no pallets. There may also be a blurring of the boundaries between “locations” – each shelf is densely and fully packed with cases abutting each other to occupy every inch of space on the shelf.
High density case storage is often seen with fashion apparel, cosmetics, shoes, medical implants and other such products that by definition have a high number of SKUs to account for sizes, styles, colors, and seasons. Other products that use high density storage are irregularly shaped items such as rugs, furniture or home decoration products.
A generally common feature of high-density case storage is that the cases are stored single-deep. This is to usually enable pickers to more easily identify and locate the products during the pick process. It is also done to ease the process of cycle counting and inventory counting – multi-deep storage of cases at high density would make it extremely difficult to both locate as well as pick cases during order fulfilment. Examples of high-density case storage are shown in Figure 1.
While high density case storage offers advantages of increased warehouse space utilization, it is critical to maintain high accuracy of inventory location and know exactly where a given case with a given SKU is, so that pickers can know exactly where to go and be assured that the case/SKU that they are looking for is present in exactly the right location. Even small mis-placements of the cases – even if within the same shelf – can result in lost productivity if pickers have to spend their time searching the entire shelf for a particular case/SKU. Conversely, if a case is “misplaced” for whatever reason, it becomes very hard to locate that case because of the high density of storage and the sheer volume of cases in the facility. Given that these DCs typically store hundreds of thousands of cases at a given time and pick thousands of cases each day to fulfill orders, even a 99% accuracy is inadequate; target location accuracies for such warehouses often need to be upwards of 99.7% to maintain the flow of pickers and not delay shipments due to unlocatable inventory.
Achieving and maintaining such a high accuracy – especially at large DCs with high SKU count, high density, and high volume — can be a significant challenge. The traditional method is of course cycle counting – multiple cycle count associates are dedicated to the task of verifying the locations of various SKUs and cases on an everyday basis, and “cycling” through the DC or warehouse at a specified frequency, such as every month or every quarter. But given the nature of the products stored in these warehouses, the inventory also moves at a high “velocity” – which makes such infrequent cycle counting less useful. This of course poses the classic cycle counting cost vs. accuracy tradeoff: To maintain very high accuracy, the cycle count frequency needs to be very high (ideally 2-4 times per month), but the labor costs of such a high frequency cycle count pose an undue burden on the operation. An example of a densely packed location with multiple units of a SKU and multiple SKUs is shown in Figure 2.
Warehouse and DC Operations leaders are therefore naturally turning to automated solutions for cycle counting. There are three “classes” of automated cycle count solutions available in the market today. Below, we provide a synopsis of each approach and an analysis of why StorTRACK from Vimaan is an ideal solution for automated cycle counting of high density case storage.
● Drones automate the cycle counting process by flying from one location to another, using machine vision cameras to scan barcodes and simultaneously associating the location of the drone at the time of the barcode scan to that of the inventory item.
● StorTRACK is a computer vision enabled “sled” that can be picked up by any Material Handling Equipment (MHE) such as a forklift, cherry picker or similar equipment. The unit is manually operated and captures the entire face of the rack as it moves down the face of the aisle. It “reconstructs” the inventory in the racks and provides a true digital “twin” of the racks – reading barcodes, extracting text, and identifying the precise locations of the cases.
Below we provide a comprehensive and objective comparative analysis between StorTRACK and drones for automated cycle counting of high density case storage. The analysis compares the solutions on a few dimensions as listed below, and on each of these factors, we show how StorTRACK vastly outperforms drones: in fact, we explain why drones simply cannot handle high density case storage applications.
1. Identify, locate and count cases
2. Highlight discrepancies against the WMS
3. Provide “search” feature to locate an item
4. Throughput and warehouse associate productivity
Identify, Locate and Count Cases
High density case storage poses several challenges for an automated cycle counting product that StorTRACK handles better than drones.
● The high-density results in labels being placed very close together (sometimes within inches of each other). Many of the cases are identical to each other; so the labels can also be identical – which in turn requires a solution that can distinguish and separate two labels that may be identical to each other.
● The computer vision technology used by StorTRACK’s can read and “disambiguates” such labels no matter how close they are to each other. It detects, identifies and separates the cases based on AI model training. It also uniquely associates each label to a particular case on which the label is placed. This model training is effective regardless of whether the labels are unique or identical (non-unique) to each other.
● Drones cannot separate or disambiguate between labels that are placed closely together because they use a single camera that is based on machine vision and do not have the spatial resolution to separate out closely spaced labels. This problem is even more acute when the labels are non-unique and identical to each other; drones cannot distinguish between one case and a neighboring identical case that has the same label.
● Often a case may not have a label (because it is missing or the label is not facing the aisle), or it may have an unreadable label (because the label is damaged or partially obscured.) In these situations, it is important to detect and highlight such “non-compliance”.
● StorTRACK independently “detects” each individual case and associates each label with a case. In a situation where there is a case but no label associated with it, StorTRACK clearly highlights it visually by outlining the case and its location visually on the shelf so that an associate can take action and apply a label.
● Drones only look for labels that are spatially separated and unique. If a case is missing a label, drones will not be able to highlight such cases.
● Some situations require a cycle counting solution to “count” the number of cases of a particular SKU in a specific location, even if some of them do not have labels facing outward or labels that are too small to be read.
● StorTRACK’s computer vision technology gives it “human-like” capabilities. As a result, it is able to identify and count cases very accurately, even though the cases look identical and may be tightly packed against each other.
● On the other hand, drones do not get a “full view” of the shelf but are narrowly focused on locating and reading each barcode. As a consequence, they are unable to count cases or items on a shelf.
● Warehouse operators need very precise location identification of cases in order to minimize the time required to search for an item. This requires location accuracies that may be as small as a few inches.
● Because of the extensive sensor capabilities, StorTRACK has very fine mapping and positioning capability for each of the cases and the labels identified. It calibrates against the locations of the fixed warehouse assets and is thus able to provide accuracy to within inches of where a case or a label is.
● Drones use machine vision based barcode scanners and therefore are unable to pinpoint the location of the label within the field of view of the camera.
Some examples of how StorTRACK identifies cases, pinpoints discrepancies, and counts cases are shown in Figure 3.
Highlight Discrepancies against a WMS
Since StorTRACK can precisely locate and count cases and labels, it can also compare these locations against the WMS and highlight discrepancies. Each individual discrepancy and non-compliance is provided in an easy to see, visual format, thus enabling easy reconciliation and update of the WMS by the associate. An example of such a report is shown in Figure 4.
Provide Search Features to Locate a Missing Item
StorTRACK builds a “map” of every item and location in the DC. Consequently, it can serve as a “Google Street View” of the entire storage area and provides search capabilities. If an associate is looking for a particular SKU, the ViewDECK application that comes with StorTRACK can provide an easy to see, visual highlight of all the locations where that SKU was last found.
Throughput and Warehouse Associate Productivity
StorTRACK really shines at productivity in a high-density case storage situation. StorTRACK’s scan speed does not depend on the number of cases or labels on a rack face. It can scan an entire 30’ high, 8’ wide bay in 30-40 seconds – even if there are over a hundred cases in that bay! In contrast, drones must locate and stop at each label to read it, which could take several minutes per bay.
Read this case study see how a leading manufacturer doubled inventory accuracy after deploying StorTRACK in their high-density case storage environment.
To learn how StorTRACK can work in your warehouse or DC, Contact Us.
Q. What is high-density case storage and how is it different from standard pallet storage?
High-density case storage refers to warehouses and DCs where inventory is stored directly at the case or carton level on shelves, without pallets. Cases are typically stored single-deep so pickers can identify and locate products efficiently. It’s common in fashion apparel, cosmetics, footwear, medical implants, and other high-SKU industries.
Q. Why is cycle counting harder in high-density case storage environments?
High-density layouts pack cases tightly together, often with identical or closely spaced labels. Inventory also moves at high velocity, meaning infrequent cycle counts quickly become inaccurate. Achieving and maintaining 99.7%+ location accuracy requires very high cycle count frequency which is prohibitively labor-intensive with manual methods.
Q. Can drones handle cycle counting in high-density case storage?
Drones struggle significantly in high-density case environments. They rely on machine vision-based barcode scanning, which cannot disambiguate between closely spaced or identical labels, cannot count unlabeled cases, and cannot pinpoint precise inch-level locations. They also slow down significantly because they must stop at each label individually.
Q. How does StorTRACK handle cases with missing or damaged labels?
StorTRACK detects each individual case as an object, independent of its label. If a case is present but has no readable label, StorTRACK visually outlines and flags it so an associate can take action. This is a capability that purely barcode-driven drone systems cannot replicate.
Q. How fast is StorTRACK in a high-density case storage aisle?
StorTRACK can scan an entire 30-foot-high, 8-foot-wide bay in 30 to 40 seconds, regardless of how many cases are in that bay. In contrast, drones must stop at each individual label, which can take several minutes per bay, making StorTRACK significantly faster in dense environments.
Q. What does StorTRACK’s discrepancy reporting look like?
StorTRACK compares its scan results against the WMS and surfaces each discrepancy in a visual, easy-to-read format. Associates can see exactly where a mismatch exists and reconcile it without manual searching. The ViewDECK application also provides a “Google Street View”-style search so operators can locate any SKU instantly.