The Levey–Jennings chart is a type of statistical process control (SPC) chart, typically used in laboratory quality control applications. It is a chart that uses very similar to the Individual-Range chart, the major difference being that it only uses the Primary individual data point graph of the chart and does not include the Secondary range graph. Also, the Levey-Jennings chart uses the Westgard rules which utilizes tests involving 1-, 2- and 3- sigma control limits. For proportion data, it uses 10-20-30 percent for the control limits.