UCHART Statement: SHEWHART Procedure
| Overview: UCHART Statement |
The UCHART statement creates 
charts for the numbers of nonconformities (defects) per inspection unit in subgroup samples containing arbitrary numbers of units.
You can use options in the UCHART statement to
specify the number of inspection units per subgroup
compute control limits from the data based on a multiple of the standard error of the plotted values or as probability limits
tabulate subgroup summary statistics and control limits
save control limits in an output data set
save subgroup summary statistics in an output data set
read preestablished control limits from a data set
apply tests for special causes (also known as runs tests and Western Electric rules)
specify a known (standard) value for the average number of nonconformities per inspection unit
display distinct sets of control limits for data from successive time phases
add block legends and symbol markers to reveal stratification in process data
superimpose stars at points to represent related multivariate factors
clip extreme points to make the chart more readable
display vertical and horizontal reference lines
control axis values and labels
control layout and appearance of the chart
You have three alternatives for producing charts with the UCHART statement:
ODS Graphics output is produced if ODS Graphics is enabled, for example by specifying the ODS GRAPHICS ON statement prior to the PROC statement.
Otherwise, traditional graphics are produced by default if SAS/GRAPH® is licensed.
Legacy line printer charts are produced when you specify the LINEPRINTER option in the PROC statement.
See Chapter 3, SAS/QC Graphics, for more information about producing these different kinds of graphs.