This software may not be used for any commercial purpose, modified, or or otherwise distributed without written permission from the author.
This Excel template allows you to simulate control charts having a variety of out of control conditions.
The template has three primary worksheets: Data and calculations, x-bar chart, and R-chart. Click on the appropriate tabs.
Enter data ONLY in yellow-shaded cells. Do not change the formulas in any other cell.
1. Enter the number of samples, sample size, and number of decimal places in the range E3:E5.
You may generate up to 50 samples with sample sizes of 2 to 10, with a specified number of decimal places (1 or 2 recommended).
Larger number of decimal places will require changing the cell widths.
2. Enter a desired process capability index (Cp) and upper and lower specification limits in the range L3:L5
The mean and standard deviation of individual observations are calculated from these parameters.
The nominal mean is (USL+LSL)/2; sigma = (USL-LSL)/(6*Cp)
This also allows you to generate data for process capability analysis exercises with known characteristics.
3. Enter the number of samples on which to base control limits in cell W3.
This number must be less than or equal to the number of samples specified in cell E3.
Note that the grand average and average range in cells C27 and C28 are calculated based on these samples only.
For example, to illustrate the effect of a shift in the mean of a controlled process, you might base control limits on the first 30 samples
and cause a mean shift starting at sample 31.
To illustrate the analysis for constructing a control chart by identifying out of control conditions and recalculating limits, you would base