Changing Control Chart Rules in QI Macros

Control Chart Rules for determining unstable points and conditions vary among the experts. QI Macros lets you select from among industry standards including Montgomery, Nelson-Juran, Westgard, AIAG, Western Electric and rules used in Healthcare. You can also create custom rules.

QI Macros Control Chart Rule Options

Montgomery control chart stability rules

QI Macros default rules are the Montgomery rules from Introduction to Statistical Process Control, 4th edition pp 172-175, Montgomery.

How to Change Control Chart Stability Rules in QI Macros

  1. Click on the QI Macros menu, Control Charts and then Control Chart Rules.

    stability-rules-menu
  2. Select the control chart rules you want to use. Depending on how fast your version of Excel is, you should see QI Macros updating the rules file.
  3. Now just run a chart and the new rules will be applied.
  4. To check which rules are active, click on QI Macros, Control Charts, Control Chart Rules and then Show Current Rules. The active rules will be shown in the column labeled "n (points)." In the example below, you can tell that Juran's rules are active because the values in the "n (points)" column are equal to Juran's rules.
    show control chart rules
  5. Any changes made to the rules are "permanently" made. The rules will not reset if you close and reopen Excel or shut down and start up your computer.
  6. To reset the rules to the defaults or to another set of rules simply click on the Control Chart Rules menu and select a new set of rules or Montgomery's rules to go back to the default.

How to Create Custom Control Chart Rules in QI Macros

You can set your own custom stability rules using QI Macros as follows:

  1. Open Excel
  2. Open the Control Chart Rules file in
    My Documents\QI Macros Test Data\ControlChartRules.xls
    x

    If there isn't one in that location, use:
    Program Files\QI Macros\ xlstart\QITemplates\ControlChartRules.xlsx
  3. If there isn't one in that location, use:
    Program Files\QI Macros\ xlstart\TestData\ControlChartRules.xlsx

  4. The file will open, but it will be hidden in Excel. To unhide the file in Excel 2010-2019 and Office 365, select View then Unhide.

    unhide control chart rules
  5. The control chart rules file will allow you to turn a stability test off by changing the value in the Apply rule column from True to False. Just click on a cell and change the value using the pull down arrow.

    change rule true or false
  6. You can also change the number of points required for each test by changing values in the n (points) column. Just select the cell and select one of the options using the pull down arrow.

    change control chart rule numbers
  7. After you make your changes, save the Control Charts Rules file, re-hide it and then completely close and re-open Excel. Note: changes will not take effect until you close and re-open Excel.
  8. Once you have re-opened Excel, select the "Control Charts (SPC)" drop-down, choose "Control Chart Rules", and select "Custom Rules":
  9. custom-control-chart-rules

  10. Once you have done so, select "Show Current Rules" - you should now see your custom rules listed as the current rules.
  11. To change back to the defaults, from the QI Macros menu, simply select Control Charts, Control Chart Rules, Montgomery (Default Rules). Note: There is no need to close and re-open Excel when making changes via the menu.

Note: If your custom rules are not listed, go into Excel and select Open > My Documents\QI Macros Test Data\ControlChartRules.xlsx. After opening, unhide the file - are your custom rules still listed? If not, re-enter your rules, choose Save, View > Hide, close Excel and reopen - the Custom Rules should now be the current Control Chart Rules.

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