About the Statistical Analysis of Autolog Variables

You can statistically analyze the value you enter for autolog variables using one of the following charts:

• Quartile chart: A type of quantile, which divides the number of data points into four quarters. The Quartile chart is an indicator of the range of values you can enter for a variable. In addition to the Quartile view, you can access the specification-limit view.
• Whisker chart: A visual representation of the range of values for statistical items associated with the variable.
• Statistical Process Control (SPC) chart: Contains one of the following charts to help determine if a process is stable and predictable:
  • X-Bar and Range
  • X-Bar and Sigma
  • X-Bar and Moving Range
  • P chart
  • U chart
  If a variable is configured with other SPC variables, its value will not be plotted on the SPC chart.