Walter Shewhart, the pioneering statistician who invented mathematical process control during the 1930s at Bell Laboratories in the USA, initially developed the idea of the PDCA cycle. It is also referred to as "the Shewhart Cycle." From the 1950s on, it was promoted quite successfully by the popular quality control authority, W. Edwards Deming and is thus referred to by many as the Deming cycle or wheel of Deming.
PDCA stands for "plan, do, check, and act." The PDCA cycle is a sequence of the four phases that one must go through to get from "problem faced" to "problem solved." as shown in the PDCA infographic template.
Plan: Identify the root cause of the issue and then schedule a modification or measure for enhancement.
Do: Execute the adjustment or evaluation, ideally on a small scale or pilot scale.
Check: Check to see how the intended outcome has been reached, what has gone wrong, and what has been learned.
Act: Implement the changes if the intended effect has been obtained. Repeat the procedure using information learned from the previous cycle if the outcome was not as expected.
While this is a continuous loop, somewhere one needs to start. One will usually start at the check stage as a problem-solving method to determine what the specifications are and what the truth is. Whet decides the difference between fact and requirements
