PDCA Improvement Methodology: Plan-Do-Check-Act

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The Cycle With Many Names

Whether you call it the PDCA Cycle, the PDSA Cycle (with the S being for Study), Deming Cycle, or Shewhart Cycle, one thing is for certain: Plan-Do-Check-Act will help you to implement improvement in your organization. PDCA has many names because it has been found to be an incredibly useful tool in project management, Six Sigma, and process improvement. Just like it sounds, the Shewhart Cycle has four steps:

  • Plan
  • Do
  • Check
  • Act

You should use PDCA any time:

  • you need to make continuous improvements to a process.
  • you are designing a new process.
  • when you are implementing changes into an existing process or project.
  • when you need to define a work process.
  • when defining a new service or product.

Read on to learn more about each of the steps involved in the PDCA improvement methodology as well as the tools involved with the process.


“Plan” is really a two-step process. The first step consists of identifying and defining a problem existing within a process. The second step involves analysis of this problem. During these two processes, many tools and steps will need to take place including:

  • Determining the root cause of the problem.
  • Determining the interventions necessary to correct the problem.
  • Determining what the expected outcomes are.
  • Determining who the responsible parties will be for the improvement of the problem.
  • Scheduling the steps of the correction.
  • Planning for resources.
  • Justifying the need for the improvement.
  • Determining the metrics for the improvement.
  • Mapping the process using a flowchart or other helpful tool.
  • Collecting any data related to the problem.


Once the plan has been created, the project scope statement signed off on, and the schedule made, it’s time to execute the plan. During this phase, a solution will be:

  • Implemented on a trial basis.
  • Continuously checked (see the next step) for efficiency.
  • Permanently implemented (if the trial is successful).
  • Measured for performance.
  • Used to train employees on quality improvement.


Once the implementation of the solution has been started, using the PDCA improvement methodology, you will need to track the performance of this solution over time. Take time to compare the product or service quality before and after the implementation. Answer the following questions:

  • Did the implementation of a change reach desired results?
  • What about the implementation or change worked well?
  • What did not work?
  • What was learned from the implementation?

All knowledge garnered from the trial run should be acted upon - should you not achieve your desired results, for example, then you need to go back to step one and take a look again at your root cause analysis. Perhaps you identified the wrong cause of your problems. Also, make sure to communicate with others on what you found.

If, on the other hand, you find that you achieved your desired results, you can move on to the “act” phase of the Deming Cycle.


Should your plan work (and after a few attempts at tweaking your process, it should), then it is time to standardize your process improvement and implement it across your business practices. During this final phase of the PDCA cycle, you will want to:

  • Identify any training needs for full implementation of the improvement.
  • Fully adopt the solution for process improvement.
  • Continue to monitor your solution.
  • See if you can’t improve the solution through further implementations
  • Find other opportunities for improvement.

PDCA improvement methodology, like Total Quality Management, is a continuous method. That means that you don’t stop working through the PDCA cycle once you’ve achieved one goal. Instead, you “lather, rinse, repeat” and continually find ways to improve your products, services, and processes over time.