Choose Xbar Options, then click the Parameters tab.
![control chart minitab control chart minitab](https://goleansixsigma.com/wp-content/uploads/2015/08/XBarRChart-Minitab.png)
This can be desirable in many cases-for example, when you have a new process.
![control chart minitab control chart minitab](http://2.bp.blogspot.com/-27uLnFWX8rY/UZw3us3SGSI/AAAAAAAAAGs/NUUvC2qqGRg/s1600/Capability+Run+2.jpg)
When you add or change a value in the worksheet, by default the center line and control limits on a control chart are recalculated.
#Control chart minitab how to
In this post I will show you how to take control of your charts by using Minitab Statistical Software to set the center line and control limits, which can make a control chart even more valuable. They know the importance of monitoring their processes with control charts, but many don’t realize that they themselves could play a vital role in improving the effectiveness of the control charts. I have been using Minitab since 1979 and have never had to question the calculation outcomes.As a member of Minitab's Technical Support team, I get the opportunity to work with many people creating control charts. This can be compared to the Variables Chart for Groups section and the formula differences can be noted. I hope this points you in the right direction. In Minitab 15, go to the Minitab Help file, then Help, Help, then select Methods and Formulas under the References section, then select Control Charts under Quality and Process Improvement section then select Variables Chart for Individuals and Methods for estimating standard deviation. Look at the help file in Minitab as well as a good basic statistics book like Duncan, Juran, or Grant & Leavenworth for help with your formulas. Also – did you select a moving range to go with the I chart? If so, what did you select for n for the moving ranges? All of this will impact the control limit calculations.
![control chart minitab control chart minitab](https://www.researchgate.net/publication/332976150/figure/fig1/AS:756839209791488@1557455937180/Main-effects-plot-for-means-output-from-Minitab-v14.png)
The formulas for the I chart are different than for an X-Bar and R chart. You mentioned you were plotting an I chart.