Bar Code Quality Mythbusting: Part 2
There is a widely held belief these days that bar code quality isn’t as big an issue as it once was—say back in the 80’s and 90’s. We have consistently and emphatically taken the position that this belief is simply not borne out by the facts. Recently we stated that poorly performing or non-performing bar codes used to be an inconvenience, but today they are a factor in retail point-of-sale customer loyalty and even life-threatening in healthcare delivery environments. See “Bar Code Quality More Important Than Ever”. Consider that article to be Bar Code Quality Mythbusting: Part 1.
The very reason for the belief that there are fewer bar code quality problems may be the actual cause of many bar code problems
To be sure we experience fewer problems in the checkout line at the local supermarket these days but perhaps not as few as we may think. Those of us who pay close attention to the transaction and study the receipt tape are more aware than others that problems at retail point-of-sale continue, but they have become more subtle. The very reason many people give for the supposed disappearance of bar code quality problems at the checkout may be the actual cause of these stealth problems.
Improved print technology does not produce better bar code quality — better operator diligence does
There can be no doubting that significant improvements have been made in both areas, but to conclude that bar code quality is no longer a problem is highly overstated. Fewer scanning problems does not equate to a decrease in the importance of bar code quality—in fact, quite the opposite. Bar codes are so ubiquitous and so mission-critical, there is far less tolerance for bar code failure than ever before. With regard to printing technology, the emergence of more ways of marking the product or package with a bar code does not equate to better process control. The ISO test lab at Barcode-Test LLC sees a lot of high-tech printed bar codes that grossly exceed element width tolerance and trigger failures in Modulation, Decodability and Decode. And the technology itself is often not the root cause: lack of operator diligence is the most prevalent cause. Some things technology just cannot change.
Improvements in scanner technology is a much more subtle, even stealthy issue. A quick review of your receipt tape from a trip to the supermarket may make a believer out of you. Modern camera-type bar code scanners are much more fault tolerant than older laser and linear imager scanners—but there is a limit that the most aggressive scanners violate all the time: it’s called transposition or substitution error.
Improved scanner technology is a more stealthy bar code quality issue–it can actually conceal actual problems
Here what happens: a damaged or badly printed bar code is presented a super aggressive modern scanner. Through its high-tech decode algorithm and high image resolution it can capture data from damaged, distorted, blurred, scratched, low height and low contrast bar codes. But fault tolerance in most 1D bar codes can only correct for a missing or damaged elements in only one encoded character—not an entire bar code or significant portions of it. So what happens? The scanner firmware fills in the questionable or missing attributes with what it “thinks” is supposed to be there. Is it correct? Is it incorrect?
Meanwhile, the checker is sliding cans and boxes and apples and artichokes through the scanner at top speed, and the little “beep” is all anybody is paying attention to—except for the occasional bar code industry geek like me who is still fascinated by this technology, pays it close attention to what’s happening, and studies the receipt tape. I can tell you from personal experience that scanning errors happen a lot. Most people don’t notice. It is not nefarious, there is no conspiracy, but it is happening.
Bar code quality is most definitely not less of a problem than it was in the early days—in fact it is more of a problem not only because bar codes are more important today than ever before, but also because we are not as aware of it as we were back in the old days.