Quality and Reliability Methods - SAS

66 Interactive Control Charts Chapter 4
Control Chart Builder Options
– Westgard Rules lets you select which Westgard statistical control tests to enable. Because Westgard
rules are based on sigma and not the zones, they can be computed without regard to constant sample
size.
– Test Beyond Limits enables the test for any points beyond the control limits. These points are
identified on the chart.
Note: For more information about tests, see “Tests for Special Causes” on page 39 in the “Statistical
Control Charts” chapter
Note: For a description of the Rows, Graph, Customize, and Edit menus, see the Using JMP book.
Statistic
Change the statistic represented by the points on the chart using the following options:
Individual
Average
creates a chart where each point represents an individual value in the data table.
creates a chart where each point represents the average of the values in a subgroup.
Range
creates a chart where each point represents the range of the values in a subgroup.
Standard Deviation
subgroup.
creates a chart where each point represents the standard deviation of the values in a
Moving Range on Means
means.
Moving Range on Std Dev
standard deviations.
computes the difference in the range between two consecutive subgroup
computes the difference in the range between two consecutive subgroup
Moving Range
creates a chart where each point is the difference between two consecutive observations.
Note: The Average, Range, Standard Deviation, Moving Range on Means, and Moving Range on Std Dev
methods appear only if a Subgroup variable is specified. The Individual and Moving Range methods appear
only when no Subgroup variable is specified.
Sigma
Change the method for computing sigma using the following options:
Range
uses the range of the data in a subgroup to estimate sigma.
Standard Deviation
uses the standard deviation of the data in a subgroup to estimate sigma.
Moving Range uses the moving ranges to estimate sigma. The moving range is the difference between
two consecutive points.
Levey-Jennings
uses the standard deviation of all the observations to estimate sigma.