Opposing sides of the inline versus offline verification debate sometimes try to make it sound like one or the other is unquestionably superior. It’s a bit like claiming that air is better than water when in fact both have their place—and neither is intrinsically better than the other.
The advantages of inline verification are self-evident. You get 100% automatic verification of every barcode exiting a printer or moving down a conveyor. If the barcodes are, for some reason, low or deteriorating quality, the automatic verification system can become a very demanding master if human intervention is required to restart the system or deal with an overflowing shunt area. Likewise it can become a major source of label and ribbon waste if it automatically (and with increasing frequency) backfeeds and reprints bad labels. The key to intelligent use of inline verification isn’t “set it and forget it” as is sometimes implied by the purveyors of these systems. Set it, forget it–and regret it. Verification is most effective in situations where it is employed to monitor and confirm the effectiveness of in-place quality systems—not as last line of defense in a system devoid of quality procedures and practices. This is equally true of inline as well as offline barcode verification.
Offline barcode verification can do some things inline verification usually cannot—or does not. Product lookup, for example, is more typically an offline barcode verification option. In addition to reading and grading the barcode based on print quality and data structure, an offline verifier can also refer to a lookup table or simple database to match the barcode data to a known product, thus confirming that the right barcode is on the product or item. Of course this confirmation does not occur without human intervention—a person looking at the lookup item description on the verification report.
This brings up an important point shared by both inline and offline verification. Both types of barcode verification produce data in the form of a verification report—data that must be looked at and interpreted by a human in order to act on it. Things change as a process proceeds. In a thermal transfer printing process, for example, print head temperatures can increase over time. Increasing print head temperatures cause X dimension growth and print gain, which is reported as a degradation over time of the parameter Modulation. Neither inline nor offline verification systems do anything more than report this. The printing system does not detect it and compensate for it. An operator may detect that the inline system is starting to reject more and more labels as the print run proceeds, but without looking at the data, it is impossible to discern what adjustments are necessary. But if the inline system was put in place as part of a strategy to reduce or eliminate operator involvement, payroll savings may be offset by cost increases in label and pigment waste.
Which is better? Inline or offline verification? Wrong question. Which is right for you? Which would you rather live with?