What statistical tool was first proposed by Walter Shewhart in 1924 and is considered the backbone of statistical process control?

The statistical tool that was first proposed by Walter Shewhart in 1924 and serves as the backbone of statistical process control is control charts. Control charts are essential for monitoring the performance of processes over time by displaying data in a time-ordered manner alongside control limits. This allows organizations to visually assess whether a process is stable and predictable or if there are variations that may require intervention.

Control charts help in distinguishing between common cause variation, which is inherent in the process, and special cause variation, which can signal a need for corrective action. Their importance in quality management and continuous improvement makes them a foundational tool in Total Quality Management (TQM) and related methodologies, enabling teams to maintain consistent quality and enhance processes effectively.

While other options such as Pareto charts, fishbone diagrams, and run charts serve valuable purposes in quality management, they do not provide the same real-time monitoring capabilities and focused approach to understanding process stability as control charts do. Therefore, the historical significance and practical application of control charts firmly establish their role as the backbone of statistical process control.