Quality impact, with the use of more than three sigmas in the statistical control of processes by variables

The main objective of this study is to show how the use of more than ± 3? in the formulas to determine the limits of the variables in the statistical process control charts affects the quality of the manufactured products and, consequently, the final consumer. In the research process, the induction and description methods were used to determine the required values of the parameters, constants and others used, which allow showing the proposed objective. The results in this study indicate that the use of more than ± 3? in the statistical process control formulas by variables can have a negative impact on the quality of the final product. This is because the use of wider limits may allow more variability in the process to go undetected, which may result in more defective or out-of-specification products. Consequently, this can negatively affect customer satisfaction and company reputation. Therefore, it is important to take these findings into account when setting control limits on statistical process control charts.