PDCA Cycle
PDCA (Plan-Do-Check-Act) is the fundamental improvement cycle: Plan, Execute, Verify, Standardize. It structures every improvement process into four clear phases.
The PDCA cycle (also called the Deming Circle) is the foundation of systematic improvement. Plan: Analyze the problem and plan the countermeasure. Do: Test the countermeasure on a small scale. Check: Verify the result and compare with expectations. Act: Standardize if successful, adjust if not.
The key lies in its iterative nature: After Act, the cycle begins again. There is no end state -- every standard is just the starting point for the next improvement.
PDCA prevents two common mistakes: First, implementing measures without planning (random changes). Second, closing measures without verification (no learning loop). Both lead to unstable processes.
In the KATA methodology, the PDCA cycle corresponds to experimentation: Every experiment has a hypothesis (Plan), an execution (Do), a verification (Check), and a conclusion (Act). The coaching questions in Leanshift guide through exactly this cycle.
Practical Example
A logistics team finds that picking time is too high (12 minutes/order). Plan: Rearrange pathways based on ABC analysis. Do: Test run with new layout for one week. Check: Picking time drops to 8.5 minutes. Act: New layout becomes the standard, next cycle focuses on picking height.
How Leanshift Helps
The coaching reflections in Leanshift directly map the PDCA cycle: What do you expect? What did you observe? What did you learn? What is the next step? This ensures every improvement step is documented and traceable.
Frequently Asked Questions
What is the difference between PDCA and DMAIC?
PDCA is a general improvement cycle (Lean). DMAIC (Define-Measure-Analyze-Improve-Control) is the Six Sigma variant with a stronger focus on statistical analysis. PDCA is faster and better suited for smaller improvements.
How long does a PDCA cycle take?
As short as possible. A simple experiment can be completed in one day. More complex improvements take 1-4 weeks. Important: Many short cycles are better than one long one.
Who invented the PDCA cycle?
Walter A. Shewhart developed the concept in the 1930s. W. Edwards Deming popularized it in Japan, which is why it's also known as the Deming Circle.
Related Terms
5S Method
5S is a systematic method for workplace organization and cleanliness. The five steps: Sort, Set in Order, Shine, Standardize, Sustain.
Kaizen
Kaizen means 'change for the better' and describes the philosophy of continuous, incremental improvement by all employees -- every day, everywhere.
Gemba Walk
Gemba Walk means: Go to the actual place to observe processes with your own eyes. Don't optimize from a desk, but where value creation happens.