Plan-Do-Check-Act

Plan-Do-Check-Act, also called the Shewhart cycle, the control circle, or PDSA when the third step is called study instead of check, is an iterative design and management method used in business for the control and continual improvement of processes and products. The method originated with physicist Walter Shewhart at Bell Telephone Laboratories in the 1920s, was modified by W. Edwards Deming in the 1940s, and was introduced by Deming into Japanese management practice in the 1950s, where Japanese practitioners streamlined it into its now standard four-step form, a version traceable to Shigeru Mizuno of the Tokyo Institute of Technology in 1959. Its four stages are Plan, which establishes the objectives and processes needed to deliver the desired results, Do, which carries out those objectives, Check, which evaluates the data gathered during the Do stage against the expected results and notes any changes to the original plan, and Act, also called adjust, which investigates and eliminates the root causes of any problems found and produces improved instructions, standards or goals for the next cycle. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/