Asset Tracking: The View From The Top

At an Atlanta reverse logistics facility, a real-time location system tracks assets from above—and zeroes in on doubled productivity.

During the past several years, technology vendors have touted the benefits of radio frequency identification (RFID) over traditional bar-coding tools for tracking applications. Many shippers and warehouse operators were discouraged from investing in RFID, however, due to its high cost and shortcomings, such as lack of readability.

A new technology introduced by Sky-Trax, a New Castle, Del.-based solutions provider, tackles those shortcomings head on, offering the functionality of RFID with the added benefit of 100-percent accuracy.


GENCO Supply Chain Solutions, a Pittsburgh, Pa.-based third-party logistics provider, recently installed Sky-Trax’s optically enabled real-time location system (RTLS) to eliminate operator-dependent data collection processes. GENCO manages more than 25 operations and 37 million square feet of warehouse space throughout North America, providing contract, transportation, and reverse logistics services to retail, manufacturing, and government customers.

The 3PL’s Atlanta facility provides reverse logistics services for a large retailer. “Everything from clothing to tools to household goods moves through the facility,” explains Cary Cameron, GENCO’s senior vice president, strategic processes and technologies.

Prior to implementing Sky-Trax technology, the Atlanta facility used a passive RFID system to identify pallets as they were picked up.

“GENCO spent about two years trying to implement a completely automated inventory tracking system at this facility,” recalls Larry Mahan, Sky-Trax president and COO. “It used passive RFID on pallets, and ultra-wide-band active RFID to track the trucks that carried the pallets. This technology, however, couldn’t meet GENCO’s requirements.”

The biggest challenge was accurately tracking the trucks using ultra-wide-band RFID; the facility’s RFID read rate accuracy was less than 97 percent. Another disadvantage was cost: GENCO paid about 18 cents per pallet for the RFID tags. When Sky-Trax announced its indoor tracking system in early 2007, GENCO was all ears.


Sky-Trax develops automatic data collection and location tracking systems for warehouse vehicles. Total-Trax, the system installed at GENCO’s facility, provides asset and inventory tracking by integrating two of Sky-Trax’s primary components.

One component is the Sky-Trax System, a positioning system that monitors and tracks every vehicle in the facility at all times, gathering precise location, direction, and speed data. The other component is Skan-Free, which automatically collects inventory data with an Optical Label Reader (OLR) affixed to the front of the vehicle, eliminating handheld inventory scanners, operator multi-tasking while driving, and data-entry terminals.

Using these components, the Total-Trax system records each truck’s location when its OLR reads a pallet label, which is simply a bar-code label that GENCO prints and attaches to the pallet. The user accesses an operations management screen, called Ops Man, to view full path data and speed profiles, replay events, and review vehicle movements.

“The Total-Trax system uses an Optical Position Sensor, which is mounted on a lift truck and aimed at the ceiling to read Optical Position Markers,” explains Mahan.

Based on the markers it reads, the system can determine the vehicle’s location on the warehouse floor within one inch of accuracy.

“The sensors identify the space right between the forks, so the system knows the exact location of the pallet the vehicle is carrying,” he adds. By tracking the vehicle, the system also follows the pallet it carries to the proper storage or drop-off point, such as a staging area or dock.

In late 2007 into early 2008, GENCO conducted a pilot test of the Sky-Trax System at its 328,000-square-foot facility in Atlanta. The results were impressive: all 14,000 pallets involved in the pilot study were put away with 100-percent accuracy, without traditional operator-dependent scanning. GENCO then boosted Total-Trax into full implementation.

Implementation was quick because operator training was not required. “All that is needed is an operator trained to drive a lift truck,” reports Cameron. “The operator picks up pallets, looks at the screen to see where to take them, then takes them there.” The operator does not need to punch keys or utilize an RF system.


To get the most from its Total-Trax system, GENCO upgraded its existing proprietary warehouse management system (WMS) software. The custom software layer provides additional features that enhance the WMS’s capabilities, as well as a greater range of data for ongoing analytics and operational improvements.

“The Atlanta returns center was already running a GENCO proprietary software package,” notes Cameron. “We opted to do our own internal programming so we could add some functionality that wasn’t included previously in the WMS.”

These upgrades rendered inventory placement irrelevant. A DC serving several customers does not need to allocate separate space for each customer because the system is so comprehensive and accurate that it can differentiate dispersed picks. “Sky-Trax provides the exact movement of every pallet,” says Cameron.

The Atlanta facility maintains two inventory databases. Previously, it had to rely on operators to remember which part of the facility served individual customers.

“We don’t need to differentiate now,” she notes. “With the proprietary software’s enhancements, we can update the correct database based on the type of product we pick up. Because we know the exact location where we placed it, we determine behind the scenes which database to update.”

Another software update relates to routing. Even though the previous system would direct operators where to place product, they didn’t always follow those instructions. “Because Sky-Trax provides the exact site of the lift truck, we can route the operator to the quickest- to-reach location,” Cameron says.

The quickest isn’t necessarily the closest. For example, because a lift truck can travel faster horizontally than it can vertically, the system may direct the operator to an open location on the first level, five aisles over, rather than to an open location on the fourth level, three aisles over.

GENCO’s new proprietary software also integrates task interleaving (mixing tasks to reduce travel time) with the Total-Trax system.

“For example, if an operator has just put a pallet away and there is another pallet in the vicinity that needs to be picked up, the system prompts the operator to get it,” explains Cameron.

With traditional interleaving, it can be difficult, if not impossible, to measure increased efficiency. Not so when interleaving is linked to Sky-Trax technology.

“We have full visibility of every pallet, whether the lift truck is traveling with or without a pallet, as well as what path the truck took,” Cameron says. “Having all this data enables us to measure interleaving’s efficiency.”


When GENCO opted to install Sky-Trax in Atlanta, its goal was to double “re-warehousing” productivity, which involves putting pallets away. It hit that number, and, by late 2008, the facility had processed 65,000 pallets and had achieved 100-percent pallet identification and location accuracy.

Besides these direct productivity increases, the asset tracking technologies have provided a set of data over time that GENCO can use to analyze its materials handling process.

For example, the system automatically collects data on forklift utilization (time traveled with or without product), travel distances (miles and routes traveled), idle time (non-moving time), number of times a pallet is touched, speed of the materials handling equipment, percentage of aisle congestion, and near-collision information.

In October of 2008, Sky-Trax and GENCO placed as first runner-up in the Council of Supply Chain Management Professionals’ 2008 Supply Chain Innovations Award program. CSCMP’s award recognizes teams that demonstrate excellence and innovation in addressing a significant supply chain challenge.

Now that the Atlanta installation has proven to be an unequivocal success, GENCO expresses excitement about future opportunities using Sky-Trax technology.

“Our next Sky-Trax installation will be in a DC in early 2009,” says Cameron. “The design phase is complete; now it’s just a matter of beginning implementation.”

Cameron hopes to process an additional Total-Trax installation in 2009, and install the system in several other return centers in the coming years. “One reason we like the system is its repeatability,” she explains. “Now that we are operating the proprietary software, we want to install it in all our return centers.”

The GENCO and Sky-Trax project in Atlanta was only the beginning. By tapping the experience gained on the track to implementation success, GENCO anticipates a shorter learning curve and longer list of Sky-Trax benefits in the future.


Do real-time location systems (RTLS) such as Total-Trax render RFID obsolete? Not quite, but they do claim some advantages.

“RFID can be the perfect application for some situations, but it isn’t good at tracking pallets when they are being moved from location to location,” says Larry Mahan, Sky-Trax president and COO. “RTLS reliably and accurately tracks mobile assets within a facility.”

The foremost benefit of Total-Trax over RFID is reliability. “Because Sky-Trax is an optical system, the camera can achieve 100-percent readability as long as it has line-of-sight to the bar code,” says GENCO’s Cary Cameron. “During the RFID trials we performed, and even in some of our operations that are currently using RFID, we don’t see 100-percent readability of every RFID tag.”

Another drawback of RFID is tag placement. Some RFID solutions use tags embedded in the cement floor of a warehouse, with readers mounted on the bottom of the lift trucks. “Besides being an expensive installation, the bottom of the lift truck is a rough environment for the RFID reader,” Mahan says.

GENCO also prefers Total-Trax because it is hands-free. “Our previous tracking process required the operator to use an RF device to manually scan the bar codes,” Cameron says.

Sky-Trax’s optical camera has eliminated the manual process. The operator drives up to the pallet and the camera automatically reads it. The operator then drives away without having to interact with the WMS through an RF device or any type of screen.


Total-Trax: Providing complete asset and inventory tracking, it is an integration of two Sky-Trax primary systems: Sky-Trax System and Skan-Free.

Sky-Trax System: This positioning system monitors and tracks every vehicle in the facility at all times, providing precise location, direction, and speed.

Skan-Free: This system (pictured, top left) automates data collection by gathering inventory information with an Optical Label Reader (OLR). The OLR is affixed to the front of each vehicle to identify pallet labels. Data collected by the OLR is transmitted to an onboard data processor, then transmitted wirelessly back to a data collection system, eliminating the need for handheld inventory scanners, operator multi-tasking while driving, and data entry terminals.

Optical Position Sensor: Attached to each lift truck, this reader (pictured, center) views overhead, ceiling-mounted Optical Position Markers. It uses image analysis techniques to determine each vehicle’s precise location and orientation. Vehicle location data is transmitted wirelessly to a controller, which monitors all vehicle locations and records every movement.

Ops Man: Total-Trax monitors and records the location and movement of all vehicles with this operations management screen (pictured, bottom) that displays each Total-Trax-enabled vehicle’s location. Ops Man provides full path data, speed profiles, and the ability to replay events and visualize vehicle movements.

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