A “No-read,” or unsuccessfully read barcode, is an important metric for manufacturing and logistics operations to manage. When a no-read scan occurs, a part or package is rejected and must be manually keyed in by a worker, costing time and money. If the system isn't setup to reject items, the master database could contain incomplete information which makes tracking and tracing items very difficult.
What exactly causes no-reads? It seems like a simple question, but finding the answer may involve several steps and special equipment. If there is not an obvious scratch, finder pattern damage, or quiet zone infraction, there is only one way to see what is preventing the code from being read—a barcode verifier. Barcode verifiers provide information about a code’s readability and what may be causing a decode issue. A barcode reader’s quality feedback ability stops at telling you that the code cannot be read, whereas a verifier will test all aspects of the decode process for the symbology type and highlight areas of weakness.
Any organization that produces, prints, or marks barcodes is at a high risk of wasting time, money, and resources if they are not using barcode verification to test barcodes. That’s because barcode verification is the only way to ensure codes will be readable throughout the entire supply chain.
What happens if codes are not readable? At best, people downstream—whether in warehouses or at the cash register—will need to type in information. This is time-consuming and introduces the possibility of human error. At worst, major retailers or government agencies refuse the products or issue a fine for codes that do not comply with requirements.
Here’s how to start properly testing barcodes in 3 steps:
Select the right barcode verifier: First, identify the symbology type and quality standards that are used. In order to select the right verifier model, there are a few things to consider.
What size are the barcodes being printed?
Does the barcode verifier have a large enough field of view to fit the largest barcodes and yet also have a high enough resolution to be able to see the smallest codes?
What standards do you need to adhere to? For example, GS1 or ISO standards.
How easy is the software to set up to grade against these standards?
Create a protocol: Establish a protocol for barcode testing or grading. This means verifying your codes on a consistent and regular basis and having a plan in place for corrective action if barcodes fail. Include a process for diagnosing the cause for failure and getting the printing process back on track. The protocol will need to become part of the standard operating procedure for your printing or marking process.
Do continuous or random sampling: You need to determine whether inline barcode verification or random sampling is best for you. Most barcode testing is done on a sampling basis, where codes are periodically checked at predetermined increments. Consumer packaging, for example, might be tested every 20 minutes, or every 90 minutes at most. However, technology has recently improved and a few barcode verifier manufactures now offer ISO-compliant inline verification that provides grading results and reports for 100% of barcodes printed or marked.
It is essential to understand that barcode testing is an eternal, ongoing part of your operation. Keep following your protocol and your codes will print and scan correctly. When a no-read occurs, it’s always for a reason. It’s never random. Test your codes continuously, and they will scan accurately each and every time.