 |
|||
| Achieving Six Sigma | Six Sigma Methodology | What is Six Sigma? | Overview of Six Sigma |
|
|
|||
|
|
Six Sigma X-R Charts and Six
Sigma X-S Charts The Averages and Range Chart or (X-R) is used when there is continuous data 2-10 measurements within each subgroup. It is primarily used to monitor and control the stability of a processes average value. Because the Averages and Range Chart relies on rational subgroups, it is an excellent tool for providing great insight into the process characteristics short-term variation. The X and R charts are most effective when they are used together as a matched pair. Each chart shows only one portion of the needed information concerning the process characteristic. For this reason the R chart has to be within tolerance. If the R chart is not in tolerance, then the control limits of the X chart will be inaccurate and false indication will be released. The X-S chart plots the standard deviation of each subgroup. The calculation on the X-R charts uses two data points, the highest and the lowest value, whereas the X-S charts calculate all data points. Therefore, a more accurate indicator of the process variation is indicated on the X-S chart. The X-S chart is less sensitive than the X-R chart in identifying special causes of variation, which may result in only a single value of a subgroup.
Terms and legal info | Business info | Manufacturing info | Overview business
|
Content on this site is the opinion of the
author(s).
Be sure to contact professional advice before implementing any change to
your business.
Copyright Achieving Six Sigma .com. All
rights reserved world wide.
All trademarks and service marks are property of their particular
owners.
