4 Replies Latest reply on Oct 25, 2016 7:59 AM by Ralph Stauffer

# Table Calculations for Control Charts-Very Urgent requirement

Hello all,

As per my requirement, I would like to plot a Control chart with Calculations as below:

X_Bar =  Average.

Note: Average = Window Average

R_Bar = Abs(Moving difference across table from Previous Value) / (Count of total rows -1)

Lower Control Limit (LCL) = X_Bar - 2.66 * R_Bar

Upper Control Limit (UCL) = X_Bar + 2.66 * R_Bar

where 2.66 is constant.

Can anyone please suggest me how to create Calculated fields in Tableau to achieve the above.

Please find the attached Excel with sample data and calculations in Excel for this requirement.

Monika.

• ###### 1. Re: Table Calculations for Control Charts-Very Urgent requirement

Hi Monika,

See the attached. I didn't add all the annotations, you can do those via either directly labeling the reference lines, using annotations, or embedding the worksheet in a workbook.

Jonathan

• ###### 2. Re: Table Calculations for Control Charts-Very Urgent requirement

Thank you So much Jonathan. This is the one i really looking for.

• ###### 3. Re: Table Calculations for Control Charts-Very Urgent requirement

You're welcome!

• ###### 4. Re: Table Calculations for Control Charts-Very Urgent requirement

Monika,

If you really want to construct a control chart in Tableau, this link takes you to a great tutorial. I have found it very useful as a starting point. It will do all the calculations for you, and although it uses a trend signal (not used much in control charts any more), it's very good. How to Make Control Charts in Tableau | Tableau Public