Who is credited with the Plan-Do-Check-Act methodology?

The Plan-Do-Check-Act (PDCA) methodology is credited to Walter Shewhart, who developed the concept in the context of quality control and continuous improvement. Shewhart introduced the idea of this cyclical process in the 1930s as a structured approach to problem-solving and quality improvement in manufacturing processes. The PDCA cycle encompasses planning an improvement, implementing the solution, checking the results to see if the change was effective, and acting on what has been learned to either standardize or further refine the process.

This methodology emphasizes a systematic approach to achieving and sustaining improvements in quality. While other significant figures in quality management, such as Edward Deming, built upon Shewhart's ideas and expanded them into broader quality management principles, it is Shewhart who is historically associated with the formulation of the PDCA cycle itself. This foundational framework has influenced both industrial practices and modern management strategies across various fields.