Skip to content

Six-Sigma

Six-Sigma:

Six sigma means literally six standard deviations. The phrase refers to the limits drawn on statistical process control charts used to plot statistics from samples taken regularly from a production process. Consider the process mean. A process is deemed to be “in control” at any given point in time if the mean of the sample at that time is within six standard deviations of the overall process mean to that point. In this case, “standard deviation” means the standard deviation of the sample mean. Six sigmas (= six standard deviations) is a very broad range, and the use of six-sigmas, rather than 3-sigmas, was popularized by Motorola. It poses substantial demands on the manufacturing process to limit variability of output so that a six-sigma-wide band lies within the limits of an acceptable process.

Browse Other Glossary Entries

Test Yourself

Planning on taking an introductory statistics course, but not sure if you need to start at the beginning? Review the course description for each of our introductory statistics courses and estimate which best matches your level, then take the self test for that course. If you get all or almost all the questions correct, move on and take the next test.

Data Analytics

Considering becoming adata scientist, customer analyst or our data science certificate program?

Analytics Quiz

Advanced Statistics Quiz

Statistics Quiz

Statistics

Looking at statistics for graduate programs or to enhance your foundational knowledge?

Statistics 1 Quiz

Regression Quiz

Regression Quiz

Biostatistics

Entering the biostatistics field? Test your skill here.

Biostatistics Quiz

Advanced Statistics Quiz

Statistics 2 Quiz

Stay Informed

Our Blog

Read up on our latest blogs

Certificates

Learn about our certificate programs

Courses

Find the right course for you

Contact Us

We'd love to answer your questions

Our mentors and academic advisors are standing by to help guide you towards the courses or program that makes the most sense for you and your goals.

300 W Main St STE 301, Charlottesville, VA 22903

(434) 973-7673

ourcourses@statistics.com

By submitting your information, you agree to receive email communications from Statistics.com. All information submitted is subject to our privacy policy. You may opt out of receiving communications at any time.