PDCA Cycle

A sequence of steps, designed to be repeated over and over in a continuous cycle, to solve problems or improve quality.

Also called the Shewhart Cycle, Deming Cycle, or “Virtuous Cycle”. Considered by many to be analogous to the scientific method.


• Define the problem to be solved or issue to be addressed.
• Collect data.
• Analyze the data to identify the root cause or causes.
• Develop proposed solutions and select one or more.


• Implement the selected solution(s) on an experimental or trial basis.


• Verify that the trial solution(s) have the desired effect and no undesirable side effects.


• Implement the proven solution at full scale
• Document and systematize the revised process
• Monitor the results