Quality Control of Laboratory Measurements

Levey-Jennings Control Chart

  • Levey-Jennings is a special case of Shewhart control chart for variables, designed for quality control of laboratory measurements.
  • In this graph, the X-axis can be any time, date, or run number, but is commonly the days of the month; the center-line is the mean of all observations, and the control limits are based on standard deviation.
Example Graph

Levey-Jennings Control Chart