Quality and Reliability Methods - SAS

74 Shewhart Control Charts Chapter 5
Shewhart Control Charts for Variables
To replicate this example,
• Choose the Analyze > Quality And Process > Control Chart > XBar command.
• Select the chart types of XBar and S.
• Specify Weight 2 as the Process variable.
• Specify the column Sample as the Sample Label variable.
• The Sample Size option should automatically change to Sample Grouped by Sample Label.
• Click OK.
Alternatively, you can also submit the following JSL for this example:
Control Chart(Sample Size( :Sample), KSigma(3), Chart Col( :Weight 2, XBar,
S));
Figure 5.3 X and S charts for Varying Subgroup Sizes
Weight 2 has several missing values in the data, so you might notice the chart has uneven limits. Although,
each sample has the same number of observations, samples 1, 3, 5, and 7 each have a missing value.