The deficiencies of human inspection is well documented due to the inefficiency directly related to modern inspection rates (volume of production), wandering minds during inspection operations, and visual acuity to resolve and identify defects of interest by the given Quality Assurance department.
Quality Assurance and Human Resource departments routinely overlook the required visual acuity of visual quality inspectors.
Does the inspector wear glasses? Should they be wearing glasses? Is their optical prescription current and adequate to detect the objects/blemishes? Is there a rest period to reduce eyestrain? Or, are they color blind? Do they understand the causes of the defects and expected locations?
Automated machine vision inspection systems permit inspectors to visually inspect substantially smaller sub-sets of production and thereby utilize a more discerning eye on the given parts.
I encourage you to review your QA department’s inspector criteria, and contact us with any questions and potential assistance for inspection process improvements.