MACHART Statement: MACONTROL Procedure
| Overview: MACHART Statement |
The MACHART statement creates a uniformly weighted moving average control chart (commonly referred to as a moving average control chart), which is used to decide whether a process is in a state of statistical control and to detect shifts in the process average.
You can use options in the MACHART statement to
specify the span of the moving averages (the number of terms in the moving average)
compute control limits from the data based on a multiple of the standard error of the plotted moving averages or as probability limits
tabulate the moving averages, subgroup sample sizes, subgroup means, subgroup standard deviations, control limits, and other information
save control limit parameters in an output data set
save the moving averages, subgroup sample sizes, subgroup means, and subgroup standard deviations in an output data set
read control limit parameters from an input data set
specify one of several methods for estimating the process standard deviation
specify a known (standard) process mean and standard deviation for computing control limits
display a secondary chart that plots a time trend that has been removed from the data
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 moving averge control charts with the MACHART 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.