{"id":"pdca","model_id":"PDCA","name":"PDCA","summary":"PDCA is an improvement cycle with four stages: Plan, Do, Check, Act. A team sets goals and needed changes (Plan), implements them (Do), evaluates results against the target (Check), and standardizes the change or begins the cycle again (Act). It is also called the Deming Cycle or Deming Wheel.","study_notes":["PDCA is also known as the Deming Cycle or Deming Wheel, after W. Edwards Deming, who introduced the concept in Japan in the 1950s.","PDCA is also known as PDSA, where the S stands for study.","Walter A. Shewhart developed an earlier repeating cycle called the Shewhart Cycle with the steps Specify, Produce, and Inspect.","Edward Deming expanded the Shewhart cycle into a four-step pattern for Japanese audiences.","In 1951, the Japanese Union of Scientists and Engineers (JUSE) altered Deming's framework into the PDCA cycle.","PDCA is the foundation of continuous improvement or kaizen.","In the Act stage, a team standardizes a measurable gain by updating standardized work, which ensures the improvement is stable; depending on results, it may begin the cycle again.","The Build, Measure, Learn concept popularized by Eric Ries in The Lean Startup is described as fundamentally similar to the Shewhart and Deming cycles."],"safety_notes":[],"sources":[{"url":"https://www.lean.org/lexicon-terms/pdca/","title":"Plan, Do, Check, Act (PDCA) — A Resource Guide","accessed":"2026-10-25"}],"verification":{"status":"source_checked","checked_at":"2026-10-25","values":2,"method":"llm_source_check"},"updated_at":"2026-10-25","type":"operational","spec":{"kind":"methodology","origin":"JUSE (Japanese Union of Scientists and Engineers), 1951, from W. Edwards Deming's cycle","related":["kaizen"]},"url":"https://machineschema.com/operational/pdca","license":"https://creativecommons.org/licenses/by/4.0/"}