<p>In the era of Industry 4.0, the Internet of Things (IOT) and big data analysis techniques have gradually matured, making it relatively easy for process engineers to control process accuracy. A number of studies have used statistical tests to determine whether the process quality meets the requirements of six-sigma quality level. Statistical methods can only assess the quality levels of a single process at a time, which make them inconvenient. In additional, using point estimates to assess process quality levels poses the risk of misjudgment incurred by sampling errors. To solve these problems, we used the confidence region of the mean and standard deviation and statistical testing rules to develop evaluation coordinate and quality zones of process quality analysis chart. Process engineers can plot evaluation coordinates with different tolerances on the chart and easily determine whether the quality meets requirements based on the zone that its coordinate point is in. The advantages of statistical testing and its ease and convenience of use, this approach makes it possible to assess the quality of multiple processes simultaneously. Furthermore, the proposed method can reduce the risk of misjudgment incurred by sampling errors.</p>