Inline Barcode Verification: More is (Not) Better
You can check a lot of barcodes with an inline verification system. A lot. Like every single one. That is the sole benefit to such systems, but is it really a benefit? Are there any other benefits? Promoters of inline barcode verification systems promise (or suggest) cost savings, although the initial cost of a single inline system can be several tens of thousands of dollars, a 5-to-10 time multiple of the cost of an off-line verifier. Inline barcode verification can be added to an existing machine vision inspection system, therefore adding a relatively minor cost to a much more expensive system. That is one of the savings inline verification systems promise. Just another $10,000 added to the $60,000 you are already spending. Is this “…relatively minor cost…” really a savings?
Where is the promised savings?
Another promised saving is the elimination of the person who would periodically pull samples to verify offline. In my experience, spot checking barcodes is never someone’s sole responsibility. They are also a pressman, a roving QC person, a supervisor or someone else with multiple responsibilities. Even if they are not paid an entry-level wage, how much does that actually cost over time? If the one person with barcode experience on the production floor is eliminated, what happens when something does go wrong, when the time-saving, cost-saving inline verification system detects a bad barcode?
Inline systems do trending, claims one manufacturer, as if that is unique to inline systems. Off line systems have done trending for years, writing verification reports to an ever-growing CSV file. Trending is a glance down a column of ISO parameter grades. It is quick and inexpensive.
Trending is not unique to inline verification
The real attractiveness of inline verification systems is emotional. The promises do not stand up to scrutiny. Nor do inline verification systems stand up to Installation, Operational and Performance Qualification protocols (IQ/OQ/PQ). In this case more is not better—more is more. Way more–too much.
Installation and Operational Qualification begin with the verification hardware and software, which must be ISO compliant. If the verification device and supporting software are not explicitly compliant to the relevant specification as a test device, it is not really verifying barcodes. Beware of carefully crafted language that promises “…grading to the ISO parameters…” without a certification of ISO compliance, which should be a signed and dated document that comes with the device or system.
Are Inline systems IQ/OQ/PQ compliant?
The verification system must be calibrated to a test card of known reflectance values. This is because barcode scanners decode barcodes based on reflectivity; scanners must also comply with an ISO standard that certifies that they detect reflective differences accurately. True verifiers must be recalibrated for reflectivity regularly. Inline barcode verification systems are not immune or periodic reflectance re-calibration. We have seen some manufacturers claim that their inline systems do not need to be recalibrated, as if it were an advantage. In fact, they cannot be calibrated which is definitely not an advantage—it could be a serious liability.
There are other attributes of ISO compliant barcodes verifiers too numerous to discuss here. We will address these in future articles. Inline barcode verification systems make big promises and truly deliver on few. The real costs are actually quite high and the real security they deliver is quite small. Mostly it is emotional, at a high price with high risk.