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