"The whole idea of Six Sigma is to reduce variation as much as possible in a process to increase predictability. If you get in as much of the Standard Deviations IN as possible, you have achieved this by essentially including more of the population. So the closer it is to 6 Sigma, it means that you have a large (not all) meaningful % of the population that any additional effort is going to have only marginal difference." https://www.isixsigma.com/topic/standard-deviation-vs-sigma-measurement/
one sigma = 68% confidence
two sigmas = 95% confidence
"standard deviation met" might imply that something has occurred just as predicted.