Deming Cycle

The Deming Cycle, also known as the Plan-Do-Check-Act (PDCA) cycle is a standardized problem solving approach. It is widely taught as part of most companies’ Lean training.

PDCA is built into nearly all structured problem-solving tools, such as kaizen projects, A3 reports, policy deployment, and countermeasures.

The Deming Cycle is occasionally referred to as the Shewhart cycle after Walter Shewhart. Shewhart is credited with originating the cycle in the 1920’s and 30’s, with its more recognizable namesake popularizing the Deming Cycle several years later.

The Deming Cycle’s Four Steps

1. PLAN: Plan out a change. This step of the Deming Cycle generally involves data collection, planning, and testing.
2. DO: Make the change. Implement the new process.
3. CHECK: Make sure the change is getting the desired results.
4. ACT: Follow up on the checks. Make additional changes, take a step back if that is called for, or standardize the process.

You may see a variation of the Deming Cycle that includes a “Study” step instead of the “Check” step. The PDSA version of the Deming Cycle puts more emphasis on understanding why a change does what it does, rather than just confirming that the change caused the desired outcome.