Who introduced control charts as a tool for distinguishing between two causes of variation?

Control charts were introduced by Walter A. Shewhart as a fundamental tool to differentiate between common cause and special cause variation in processes. Shewhart's work laid the groundwork for statistical quality control, allowing practitioners to visualize the stability and capability of a process over time. By using control charts, one can determine whether variations in process data are due to inherent system fluctuations (common causes) or specific, identifiable factors (special causes), thus enabling better decision-making regarding process improvements.

Shewhart’s contribution is pivotal in the realm of quality management as it allows organizations to focus their efforts on the right type of variation for effective quality control. His introduction of the control chart is often regarded as a landmark advancement in the field of quality assurance. Other figures, while influential in quality management—such as Deming and Juran—focused on broader concepts and methodologies, but it was Shewhart specifically who developed the control chart as a practical tool for distinguishing these two types of variation.