Plan, do, check, act
Definition
Plan, do, check, act is the English expansion of the PDCA acronym — a four-step iterative loop for testing and standardizing improvements. Plan the change, do it on a small scale, check the results, and act to adopt or revise.
Plan, do, check, act and PDCA refer to the same cycle — the difference is just whether you use the acronym or spell it out. Some practitioners prefer 'Plan, do, study, act' (PDSA) to emphasize that the third step involves deep analysis rather than just checking a box, but PDCA is more widely used in business contexts.
Spelling out each word is useful for teams new to continuous improvement because it clarifies what each phase actually means:
Plan is the most important phase and the most skipped. It means defining the problem clearly, understanding the current state with data, setting a specific improvement goal, and designing a testable hypothesis — not just deciding to 'try something different.'
Do means running the test — small, fast, and controlled. A pilot of one team, one week, one store, or one user cohort. The point is to generate real data without betting the whole operation on an untested change.
Check means analyzing what the data says. Did the metric move? By how much? Were there unintended effects? What did the team learn that wasn't in the plan?
Act means using that learning. If it worked, standardize, document, and scale. If it didn't, use the learning to design the next cycle. Either outcome is a win — the goal is learning, not perfection on the first try.
The cycle is visually represented as a circle or spiral — the spiral emphasizes that each cycle produces learning that improves the next round.
Examples
- Plan = reduce cart abandonment rate; Do = test a simpler checkout on 5% of traffic; Check = measure abandonment over two weeks; Act = ship the simplified checkout
- Plan = reduce onboarding drop-off at step 3; Do = add a progress bar for 1,000 new users; Check = compare step completion rates; Act = standardize or iterate
- Plan = improve code review speed; Do = add a 24-hour SLA for two sprints; Check = measure average review time; Act = make SLA permanent and add tooling
- Plan = reduce hospital readmission rate; Do = add a 48-hour post-discharge call for one ward; Check = compare 30-day readmission rates; Act = expand to all wards
Related terms
Snap a plan, do, check, act. Ship its actions.
BoardSnap turns any whiteboard — including this one — into a summary and action plan.