The answer might surprise you!
A: A barcode the scans the wrong information perfectly.
Think about it—it is a real train wreck. Here is one case history we personally witnessed.
A few years ago, we bought some vanilla yogurt along with about $150 of other stuff—a typical family grocery shopping trip. Nothing unusual happened at the register but I noticed that the receipt tape called out lemon yogurt. I thought nothing of it at the time. A few days later, back at home doing the dishes: the yogurt was eaten and the empty container was in my hand about to be discarded. Instead I brought it to the test lab. Sure enough, it scanned perfectly but the encoded information was different that the numbers beneath the barcode. Voila!
Next trip to the grocery store I sought out the store manager. Yes, there had been an inventory glitch. They kept ordering too much lemon yogurt but were chronically out of vanilla. It took them a while to figure it out; meanwhile, customers were not happy.
There are several ways this could happen. Sometimes it happens in the graphics design department. Software does not always prevent such errors when a highly creative person insets a barcode image.
A super-aggressive scanner can misread a marginal quality barcode, transposing or substituting a character or two. Barcode verification prevents marginal barcodes from causing transposition and misread problems.
A database entry error can cause an erroneous look-up at the scanner. Usually this causes a no-read but sometimes the product barcode will point to a different product in the item lookup.
This is a nightmare. That comforting “beep” at the checkout is really no comfort at all: the scanner recognized something—was it the right thing? It would be far better if the barcode failed altogether. That mesmerizing beep lulls us into a warm, comfortable acceptance that all is well, when actually a train wreck is unfolding before our very eyes.
Barcodes that misbehave in this way are difficult to detect. How can these problems be identified? Here are some ideas:
- Guard databases diligently. Making central databases accessible to many users makes them vulnerable to mistakes. If this is necessary, designate a responsible party for maintaining data integrity and checking it regularly.
- Minimize the use and distribution of multiple database copies. If this is necessary, sync them regularly to a known “golden” copy to avoid inaccuracies
- Verify and validate product barcodes to the ”golden” database. Some barcode verifiers have product lookup capability to perform this confirmation.
- Pay attention to apparent inventory anomalies such as spikes, drop-offs or unexplained supply chain errors. This could signal a barcode mis-identification
- Be aware that the comforting “beep” only means that something happened. It does not necessarily signal what you think (or hope) happened.
Does this indict barcode technology and predict its demise in favor of some new, better identification strategy such as RFID or invisible barcodes? Actually not. Alternative auto ID technologies have the same reliance on databases, which is where these errors originate.
Vision-based product recognition could avoid these problems, but that solution is outweighed by the new problems it cannot solve, such as batch or lot based recalls, best-use-by and expiration dating. Barcodes are not perfect but they are still the best, most accurate and least expensive solution for what they do.
One final thought. Consumer retail is but one situation where bad barcodes can be problematic. Databases errors can also occur in pharmaceutical and healthcare delivery systems such as bedside dosing, surgical procedures and other critical environments where the consequences could be far worse than unhappy customers. Verification and validation can detect and prevent these problems.