Tracking the inventory

Location location location

The marriage of tracking technologies is allowing companies to keep a closer eye on their assets E&T investigates.

In September last year, the BBC began a project to illustrate a typical shipping container's journey around the globe to provide a snapshot of world trade. The Box, as it's called, is fitted with a GPS transmitter that sends its position back to the broadcaster's website to allow anyone who logs on to track its progress.

Starting from Scotland packed with whisky bound for Shanghai, which it reached in late October, by mid-January it had crossed the Pacific to Los Angeles with a cargo of healthcare products, made its way overland to New Jersey loaded with measuring tapes, and was heading for Brazil with a consignment of household goods.

The BBC admits it's an ambitious project, which has already suffered a series of technical problems with the GPS unit, but for a growing number and range of businesses the ability to keep track of their goods, personnel and equipment is becoming standard practice, thanks to the marriage of a technology that began life in World War Two and some that belong firmly to the modern age.

The older technology, radio frequency identification (RFID), was originally developed to distinguish between friendly and hostile aircraft, and these days is actually a raft of technologies that allow for short-range, contactless reading of information from a low cost, compact, data source. Such a system includes data-carrying transponders called tags, and reading or read/write devices to access the data on the tags. The tags come in a variety of shapes and sizes, from credit card style to self-adhesive labels. 

A reader, either handheld or fixed, collects data about the asset from the tags or detects the tags passing a particular point in a process. This information can then be used to query or update a database to track the location of the asset or authorise the use of some resource.

There are four main types of RFID tag technology - low frequency (LF) at 125-135kHz, high frequency (HF) at 13.56MHz and ultra-high frequency (UHF) at 868-928MHz passive tags, and active tags (usually 433MHz), which have their own power supply.

Passive tags are the cheaper, with unit costs of the order of pennies now, and the three types offer different levels of reliability, different speeds and memory capacities. They also have different transmission properties. UHF tags, for example, allow a greater distance between the reader and the tag (up to about 10m) than LF (up to 100cm) and HF (up to 70cm) versions but are more susceptible to signal interference if there is packaging between tag and reader. 

Active tags, with their battery power source, allow for a much greater distance between tag and reader - up to 100m - but are bulkier, more expensive (up to about £20 each) and have a lifetime limited by their battery life, typically five to ten years. But they can have integrated sensors to allow them to collect data on temperature, vibration or radiation, for example, which can be collected by the reader as well.

Real-time location

But whether the reader comes to the asset or vice versa, an RFID system does not necessarily report the asset's current location, it only reports the location where the asset was last seen. This makes it unsuitable for many applications such as locating perishable goods stored in the wrong location, finding expensive tools or parts during a production process, or tracking personnel movements in a high-security facility. So this is where the newer technologies, grouped under the umbrella of real-time locating systems (RTLS), come in.

RTLS has been described as second-generation active RFID, and relies on a variety of wireless communications technologies to calculate and track the position of an asset in real-time. Which technology is used depends on the application (see box). Although it usually requires the use of active tags, systems are becoming available that allow passive tags to be incorporated.

So the choice of which technologies to use is governed by the application, according to system vendors. "Generally, you should first understand the business problem," says Chris Kelley, director of RFID business strategy at Intermec.

"Then ask how solving it would benefit the business, then look at what the right type of technology would be - do you want it to be a revenue enhancer or a cost cutter, do you want better infomatics or to reduce stock?"

But we're getting ahead of ourselves - after all, in these cash-strapped times, who can afford or justify such fresh investment? John Williams, marketing manager at CoreRFID says: "If your business needs to know what it's got, and where it's located, then the savings this technology brings will justify the investment.

"Times like these tend to raise the justification bar, so to speak, but payback time can be less than a year in some cases, especially if say you have few skilled staff to call on or a large number of high-value items."

Kelley adds: "In a downturn, there's a spur on companies to become leaner, by cutting stock levels for example, which forces management to evaluate and select their investments far more carefully. RFID projects tend to hold up better to scrutiny at these times."

So, first identify the business problem or application need, then map that onto the most appropriate tracking technology. Costings naturally come next but here too there are caveats.

As Williams points out: "People tend to focus on the costs of the technology while neglecting its roll-out costs, which can be substantial. You need to think through what the costs will be - not just of the technology in operation but those of getting to that stage."

He also says it's vital to look at how people will work with the technology, and what it's impact will be on their day-to-day jobs. Here Kelley adds: "You'll generally find that the benefits of RFID tracking are not as strong if you apply it to an existing business process - RFID is more a case of how to transform that process, how it allows you to do something different."

Even then, they agree, it's still too soon to reach for the cheque book, despite the fact that a full plug-and-play system can be had these days for well under £17,000 ($25,000). What they suggest is a pilot system to prove the technology, in the same environment as the final system would run. To this end, many vendors will sell you a demonstration kit consisting of one each of the main components that could probably be paid for out of petty cash.

"Having a demo site within the organisation will show how the technology can - or can't - work for the business, and helps you explore how some of the roll-out costs affect the business case," says Williams. "It's all about increasing people's confidence."

Installing new technology

Assuming the demo site proves the value of the technology, the next question is how much of it to put in. That, says Williams, is like asking how long is a piece of string. "You should put in only as much of the technology as you need to solve the application problem," he says. "So it depends on the size of the application.

"I don't think there's much need to prove that RFID and, say, GPS technologies work; the need is to show that combining them works for your business."

Kelley says: "Try to move away from a conversation about the technology. Look at the application then go and find the technology to fit it."

Of course, more than one combination of technologies may be needed to provide an enterprise-wide solution. For example, use GPS to determine the location of a cargo ship, active RFID to track the shipping containers, WiFi to track the position of the personnel and lift-trucks moving items around a warehouse, and UWB to track hazardous materials in, say, a refinery.

When it comes to purchasing, tracking technology is like any other sector in being governed by standards. "In the past, a lack of standards has hindered the take-up of the technology and its adoption in fresh applications, but that's not so much the case now, and sector-specific standards are emerging as well," says Williams.

"Yet the active tag world is still very proprietary - and if you were to look at using active tags with WiFi then that would be proprietary squared."

Kelley agrees but adds: "With WiFi, for example, you tend to have standards but with extensions. Also, in general, if you're looking at an open-loop application, such as a retail supply chain or livestock management, then standards are very important, but if it's a closed-loop application entirely within the organisation, then they're not so important."

Yes, it's another general pointer, but that's a hallmark of this technology. As Williams says: "Our biggest difficulty is that we still can't see one right answer to an application, but then I don't think there ever will be one right answer - the application areas will always be too broad."

Ubiquitous technology

The technology is therefore set to become ubiquitous. Multimode tags and multiple RTLS technologies in a single system are already available and an emerging technology called Ubiquitous Sensor Networks promises to be scalable and self-healing, pointing to its future application at the infrastructure level.

There is even talk that RFID as a discrete technology could soon disappear. AIM Global, an industry trade association that focuses on RFID, has suggested that as RFID converges with mainstream wireless technologies such as GPS, all these technologies will be absorbed into the applications they're designed for, in much the same way as artificial intelligence is embedded in just about any software that uses an algorithm.

Wisely, AIM Global does not give a timeframe here but, paradoxically in these straitened times, the issue now is not so much whether a business can afford this technology but whether it can afford not to have it.

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