technologyreview WIRELESS SOLUTIONS
View to a move
A chance encounter between managers at Kraft’s
Stockton, Calif., facility and employees of a
newly formed technology company helped point
Kraft to a potential solution: a real-time location
system (RTLS). An RTLS uses a combination of
technology—like radio-frequency identification
tags and readers, Wi-Fi, and in some cases, global positioning systems—to track and trace assets
(in Kraft’s case, trailers) in real time.
The technology vendor in this case was
PINC Solutions, a company founded in 2004
specifically to provide solutions to the problem
of finding trailers, tractors, and yard trucks in
the yard. PINC was not the first company to
bring an RTLS-enabled yard management
solution to the market; several other vendors
had beaten it to the punch. But PINC was
looking to differentiate itself from the rest by
offering a more affordable alternative.
What its competitors offered were tracking
systems that rely on active RFID tags. With
these systems, an RFID tag is attached to each
trailer, where it continuously emits a signal,
and a network of RFID readers is installed
throughout the yard. In order to determine an
item’s location, the readers simply triangulate
the tagged object’s position.
The solution PINC proposed for Kraft works
somewhat differently. Instead of using active
RFID tags on the trailers, PINC’s system uses
the less-expensive passive RFID tags. (Active
tags have a built-in power source that enables
them to emit signals, whereas passive tags rely
on the power emitted by an RFID reader to
transmit data.)
There’s another key difference as well. PINC’s system
does not require the user to set up a network of stationary
readers. Instead, the readers are installed on the yard trucks.
When a yard truck drives past a trailer or picks it up to
move it, the reader “reads” the tag. A GPS transmitter captures information on the trailer’s location at the time of the
read and then sends that information via Wi-Fi to PINC’s
Web-based yard management system.
At Kraft’s facilities, readers are also posted at each dock
door and at all exits and entrances to the yard. When the
trailer leaves the yard, the tag is removed and reused. Because
the only way that trailers are moved in the yard is by the yard
truck, the company is assured of having accurate information on the location of all trailers in the facility at all times.
As for why PINC chose to use passive tags, Aleks Gollu,
the company’s CEO, says several factors influenced that
decision. “It’s a mainstream technology that’s becoming
more and more ubiquitous in the supply chain, which
means that hardware is going to become cheaper and more
before you buy …
Interested in installing an RTLS in your own operation? Here’s some
advice from the experts:
1. Don’t buy more than you need. Before you invest, determine the
level of tracking precision you require, recommends Sanjay Chatterjee,
principal analyst with the consulting and education firm
MindCommerce and author of a recent report on RTLS, Real-time
Location Services (RTLS): Applications, Services and Company
Analysis. Without that information, he explains, you might end up buying a more sophisticated (and costly) system than you really need.
When it comes to matching systems to applications, Chatterjee
offers these rough guidelines: If you simply want to confirm that a
trailer has entered or left the yard, a system that uses low-cost passive RFID tags will probably do the job. If you need to know the
tagged item’s general location, say within 300 feet, an active RFID
solution might be the right choice for you. If you want to be able to
pinpoint an item’s location within seven to 16 feet, you’ll likely need
some combination of RFID tags and GPS.
2. Don’t overlook the secondary costs. Installation may be the
biggest expense associated with an RTLS, but deployment might be
only part of the picture. There could be some secondary costs as well,
says Chatterjee. Give some thought to what ongoing expenses the
project might entail. For example, will you be incurring costs every
year for your GPS coverage, and what will they be? If you use active
RFID tags, what will it cost to replace the tags’ batteries?
3. Be realistic about the system’s capabilities. For all their advantages, real-time location systems still have some limitations. “RTLS is
only part of an effective yard management strategy,” cautions Ian
Hobkirk, director of supply chain consulting at Forte, a supply chain
consulting and integration firm. While an RTLS is a great solution for
those companies that struggle with finding trailers in their yards, he
says, there’s still a lot of information it cannot provide. “It doesn’t give
you visibility of what’s in the trailers,” he says, “and it doesn’t correlate that with demand data on what’s needed in the warehouse.”
reliable and will be provided by many different vendors,” he
says. “And we were able to solve the problem with that technology, which is cheaper and simpler than its proprietary
and specialized active tag counterparts.”
In Kraft’s case, at least, it appears that PINC’s decision to
compete on price paid off. According to Rae, it was the
promise of high visibility with low infrastructure requirements combined with the lower cost for passive RFID tags
that convinced Kraft to give PINC’s solution a shot.
Making the change
In 2006, Kraft began rolling out the solution to its seven distribution centers. Six of the seven DCs have two yards each,
which means the PINC solution has been installed in a total
of 13 yards.
The implementation consisted of installing RFID readers
and antennas on security posts, dock doors, and spotting/yard
tractors; and putting computer equipment in security posts
and spotting tractors. It also meant ensuring that each yard
