Tukey's control chart.

This article presents the idea of Tukey's Control Chart, a method of analyzing data based on the concepts developed by John Tukey for calculation of confidence intervals for medians. The procedure is simple to implement (no need to calculate averages or standard deviations); it does not assume any distribution of the data; it can be applied to small data sets; and it is robust and not affected by occasional unusual observations (outliers). The article provides examples of the application of Tukey's Control Chart to both patients' lifestyle management and business process improvement.