Control charts Category

Summary

Univariante and multivariante control charts.

Description

Control charts are used to routinely monitor quality. Depending on the number of process characteristics to be monitored, there are two basic types of control charts. The first, referred to as a univariate control chart, is a graphical display (chart) of one quality characteristic. The second, referred to as a multivariate control chart, is a graphical display of a statistic that summarizes or represents more than one quality characteristic. If a single quality characteristic has been measured or computed from a sample, the control chart shows the value of the quality characteristic versus the sample number or versus time. In general, the chart contains a center line that represents the mean value for the in-control process. Two other horizontal lines, called the upper control limit (UCL) and the lower control limit (LCL), are also shown on the chart. These control limits are chosen so that almost all of the data points will fall within these limits as long as the process remains in-control.

Routines

Name	Summary
EWMAChart
QCCapIndexes	Calculates the Process Capability indexes p, Cp and Cpk.
QCCChart	Constructs C-Chart.
QCCumSumChart	Constructs CUMSum chart.
QCMRChart	Constructs moving range chart.
QCNPChart
QCPChart
QCRChart	Constructs R-Chart.
QCSChart	Constructs S-Chart.
QCUChart
QCWestgardRules	Compares values agains Westgard rules.
QCXChart	Constructs X-Chart ("XBar Chart").