95% confidence intervals (95% CI) are the ranges of values that are likely to contain the true value of each measurement error metric.
Minitab provides confidence intervals for the variance components, the %contribution of the variance components, the standard deviation, the study variation, the %study variation, the %tolerance, and the number of distinct categories.
Because samples of data are random, two gage studies are unlikely to yield identical confidence intervals. But, if you repeat your studies many times, a certain percentage of the resulting confidence intervals contain the unknown true measurement error. The percentage of these confidence intervals that contain the parameter is the confidence level of the interval.
For example, with a 95% confidence level, you can be 95% confident that the confidence interval contains the true value. The confidence interval helps you assess the practical significance of your results. Use your specialized knowledge to determine whether the confidence interval includes values that have practical significance for your situation. If the interval is too wide to be useful, consider increasing your sample size.
Suppose that the VarComp for Repeatability is 0.044727 and the corresponding 95% CI is (0.035, 0.060). The estimate of variation for repeatability is calculated from the data to be 0.044727. You can be 95% confident that the interval of 0.035 to 0.060 contains the true variation for repeatability.