Quality improvement charts

The qicharts package contains functions for plotting run charts and Shewhart control charts for measure and count data.

The main function is qic(), which in its simplest form takes a vector of values, plots a run chart, and performs tests for non-random variation in the data sequence. Non-random variation may be the result of deliberate process improvement or unintentional, possibly unwanted, changes in process performance.

qic() has a simple interface with a rich set of options to control data analysis and plotting, including options for automatic data aggregation by subgroups, easy analysis of before-and-after data, exclusion of one or more data points from analysis, and splitting charts into sequential time periods. Missing values and empty subgroups are handled gracefully.

The trc() function creates trellis run charts, i.e. small multiple run charts from multivariate data.

tcc() is an experimental function aiming at replacing trc() and, eventually, qic(). It allows for multivariate run and control charts in trellis layout.

The paretochart() function plots a pareto chart from categorical data.

For quick demos, run


Then read the help files


Install latest release version of qicharts from CRAN


Or install development version from GitHub