p Prime or Laney p Chart Formulas
The p prime chart (p' chart or modified p chart) works much like an XmR chart.
- Convert the p values to z values.
- Calculate the moving range of the z values.
- Use these values to calculate sigma-estimator.
- Use the sigma estimator to adjust the control limits.
Here are the formulas used to calculate a p prime chart.
Source: Improved Control Charts for Attributes, David B. Laney © 2002
- Create a p prime chart in Excel using QI Macros
- Create a p chart in Excel using QI Macros
- Other control chart formulas
The p prime chart is just one of the tools included in the QI Macros for Excel SPC Software for Excel.
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