Quality inspection in the production forces worker to become high concentrated by made them have an eye on the small product, in the meantime make decision about product nonconformities. This accelerates fatigue on workers which effect working efficiency and increases accident. After continually monitoring the performance of inspectors, it was found that certain nonconformities were more difficult to find, the number of nonconformities reported was unusual, and inspectors varied in their abilities. Furthermore, turnover rate of the quality inspection division in this company is high.