How are you tracking? RFID, bar codes and the future of the supply chain
WHOLE range of very different identification and tracking devices are becoming cost effective.
Some rely on radio frequency, others on computer chips, still others on molecular traces.
Some can scan without line of sight. Others can give the temperature reading of a product every half hour, every day, every year. Some make it possible to know exactly where a product is anywhere in the world. Others can detect a single sought after good from a batch of cargo.
The benefits to the manufacturer are in significantly reducing human error. Tiring, subjective human eyes are replaced by much faster, more accurate numeric code detectors. Product losses are reduced, downtime is slashed and the whole process from manufacturer to user is accelerated.
RFID might be the buzzword in manufacturing but it is old technology. Developed during World War Two to distinguish friendly from enemy aircraft, it has only become an affordable option for supply chain tracking in the last five years.
An authority on RFID technology is CSIRO scientist, Dr John Mo, who has just developed the world’s first global server to track RFID tagged goods using universal ONS (object naming service) functionality.
He says while people have been talking about RFID technology for a number of years, it will be extensively used by 2010.
“The problem in the past was the cost of an ID device. Only in the last two or three years have they solved the problem by being able to put large amounts of information on a relatively cheap chip,” Dr Mo told FEN.
“People are now working very hard to get the cost of the chip down by better fabrication technology. It will take a few years to make perfect but the outlook is quite good.
“You can use the location of the readers to track the products through a supply chain. You might have 15 read points from the manufacturer to different warehouses.”
According to Dr Mo, the advantages of an RFID tag over a bar code are its ability to store more information and be read over a longer distance, without line of sight.
In the internet tracking project, Mo has been using the cheapest form of RFID tag: a passive, read only label that costs between 20 and 40 cents and has a reliability rating of 98-99%.
Dr Mo explained that passive tags draw their energy from the reader and have a read range of 3 to 4 metres. That is in contrast to active tags, which are battery powered and can communicate information such as temperature to the reader.
In terms of shortfalls, Mo said RFID tags, while coated to protect against abrasion, are susceptible to damage from being knocked around. This makes them unsuitable for applications in harsh chemical and environmental conditions.
They have also been criticised for being less secure than bar codes because they do not use a unique code for each item.
Key among the critics is Greg Twemlow, Marketing Director of rival technology producer, DataDot.
“While there has been a huge investment in RFID the reality is it can be rendered useless by a cheap and readily available wireless jamming device,” Twemlow told FEN.
However Dr Mo said while jamming RFID was possible, in most cases it was not a significant threat.
“The way RFID signals work is open standard, so yes, you can jam it easily,” Dr Mo said.
“However if you were to use an illegal jamming device, anybody could see it with radar. Police would know. RFID is still the best method of product security.”
Dr Mo’s view is seconded by Mike Clarke, managing director of one of Australia’s biggest supply chain tracking solutions providers, iCrystal. Clarke told FEN: “RFID is suitable for security in a way other technology is not because it doesn’t rely on line of sight.”
In terms of process efficiency, Dr Mo said the case for RFID really comes down to two things: “eliminating human handling errors” and “getting really accurate information about where each individual item is.”
In situations where cost is a problem, conditions are harsh or continually updated product information is required, other methods of product identification might provide a better solution that RFID.
THE CASE FOR BAR CODES
At a couple of cents each, bar codes remain the best option if price is a factor and line of sight reading is practical.
Demand for bar codes is still high, according to General Manager of labelling company, Insignia, Jack Winson. Winson’s company produces RFID tags as well as regular bar codes.
“Everyone needs bar codes at the moment. It’s been building over the last ten years and won’t be dying for a long time yet,” Winson said.
“While everyone’s talking a fair bit about RFID it’s still embryonic.
“People will start using RFID tags more but it will be on the shipping cartons because it’s too expensive to put them on individual boxes.”
“It will be on expensive products that users start to see RFID tags in the shops. For instance Gillette has started putting the tags on their packages because the value of their products can handle the RFID cost.”
In all the hype about RFID it may be overlooked that bar codes have evolved as well.
Mike Clarke of iCrystal, described two-dimensional high adhesive bar codes as: “filling a gap between bar codes and RFID tags”.
While the two-dimensional bar code has been around since the 1980s, a new robust label material means the 7000 character capacity identifier – called an InfoDot - can withstand conditions an RFID tag cannot.
At 80c to $1.20 they are more expensive than passive RFID tags but according to Clarke: “they are suitable for the toughest chemical and environmental conditions.”
So far InfoDots have been used on sterilised medical equipment and on small firearms in the Victorian police force.
ALTERNATIVE TECHNOLOGIES
DataDot, markets two CSIRO-produced technologies which use microparticles for identification. They are the only identification technologies to last for the length of a product and are said to be impossible to copy.
In the case of DataDotDNA, millions of microparticles are sprayed on the surface of a product, whereas with DataTraceDNA, they are actually embedded in the molecular structure of materials, making them ideal for bulk mixtures.
The enormously complex chemical bar code can be read by a portable scanner and is extremely difficult to reproduce, a major difference from RFID.
They are a mode of identification that cannot be removed, altered or destroyed, “even if bombed or burnt”, according to Marketing Manager, Greg Twemlow.
Twemlow said the technology is intended for use in conjunction with bar codes.
“We don’t see DataTrace as necessarily replacing RFID or bar codes but as a low-cost foundation form of identification, onto which other labels, like RFID can be applied,” Twemlow said.
So far DataTraceDNA has been adopted by manufacturers requiring a robust identifier, such as in the polymers and paints industries, and also as a counterfeit prevention measure in some paper and packaging applications.
The only caveat is its low success rate in very dark black items, ink for instance.
It costs around $500 for a reader and anything from a few cents to dollars per item depending on the number of molecular codes required.
THE IBUTTON
The Dallas iButton is a reusable alternative to RFID that might be a better option for manufacturers requiring regularly updated information on product status.
The durable 16mm flat stainless steel container houses a computer chip that can transfer up to 142kbps upon momentary contact with a receptor connected to a PC.
Robert Keith is the managing director of Themodata, a company using iButtons for cold-product tracking solutions. He said the real advantages of the iButton in comparison to the RFID tag are its durability, high-security and non-reliance on battery power.
“iButtons can go on a shipment of wine coming to Australia on a two month journey from the Panama Canal and give a temperature reading every half hour until they get here,” Keith said.
“They are also incredibly robust. A customer came back to me with a button three years old and squashed flat but it was still working.
“The iButton can’t be copied like with an RFID tag because each button has a unique serial number,”
As with RFID, iButton read heads can be connected to the internet so data can be read anywhere in the world.
The reader technology costs $50, software is free from Dallas and each iButton cost between $20 and $35 depending on quantity.
“Most companies using the iButton have a few hundred and will put around four buttons in each container of cold food for instance,” Keith said.
The iButton’s greatest limitation is its size.
“Bar codes are a better option for putting together products with very small parts because at 16mm round they are too chunky for intricate goods,” Keith said.
“We will eventually start using RFID more, but that’s mostly to do with customer perception. The only time they are really better than the iButton is if you need to find out exactly where a product is.”
RFID might have been the biggest and best identification device in WWII but since then the whole shelf of product identification technologies has expanded to include technology like the iButton, the InfoDot and DataTraceDNA.
At less than 40 cents, RFID tags may be the best product identification method but in applications where it is not suitable, it is worth considering some even newer alternatives.
8 February 2006 http://www.ferret.com.au/articles/ba/0c0390ba.asp
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