Disciplined approach to off-line sampling will deliver results.
To achieve off line sample barcode verification, it is essential that you use equipment which conforms to ISO/IEC 15426-1 standards. In-line barcode verifcation cannot be achieved to the ISO standard but equivalent grades can be achieved (see Cobalt Sentinel).
Accredited, calibrated equipment must be used by trained operators as part of a regular sampling process to introduce discipline to barcoding practices and accordingly deliver the best results. Off-line testing is a rigorous process which audits barcoding procedures, but it is essential and when it comes to barcoding best practice.
If a faulty bar code is identified, corrective action can be taken. The quality of the sampling method and the speed of the interpretation of results is critical to implementing an effective procedure to capture early failures and react before production, packing, and distribution has been executed.