What is the (PDCA) Plan, Do, Check, Act Cycle?

What is the PDCA cycle?

PDCA (Plan, Do, Check, Act) is a time-tested methodology that forms the backbone of continuous improvement in various industries. The PDCA cycle, which embraces simplicity and systematic progression, facilitates problem-solving and process improvement by following four distinct stages. These stages create a circular flow that promotes continuous refinement and adaptation.

The PDCA cycle provides a structured approach that can be tailored to various scenarios, whether you’re looking to address specific organizational challenges, standardize processes, or foster innovation. This article delves into the essence of PDCA, examining its four phases, applications, and why it is such an effective tool for continuous growth and improvement. Join us as we unpack the PDCA cycle’s dynamics, providing insights and practical advice on how to effectively apply this time-tested methodology in your organization or project.

What is PDCA?

PDCA (Plan, Do, Check, Act) is a four-step methodology for continuous improvement and problem solving in a variety of organizational processes. It starts with planning (Plan) a change or solution, then doing (Do) it on a small scale. The results are then evaluated (Check) to determine the effectiveness of the plan, leading to the final action (Act) of either broadly implementing the change or revising the plan. The cyclical nature of PDCA encourages continuous refinement and adaptation, making it a versatile tool for improving quality, efficiency, and innovation in a wide range of industries and settings.

Why use PDCA?

The PDCA (Plan, Do, Check, Act) cycle is an indispensable tool in the world of process improvement and project management, and here’s why it’s so widely embraced:

1. Simplicity and Structure:

PDCA offers a simple and structured approach that anyone can follow. Its four-stage cycle – Plan, Do, Check, Act – provides clear guidelines that can be applied to various problems and processes. This simplicity makes it accessible to team members at all levels, fostering inclusivity and alignment.

2. Adaptability:

The cycle is not confined to a specific industry or project type. It’s a flexible framework that can be adapted to different contexts, whether it’s manufacturing, logistics, or healthcare. This adaptability makes it a universal tool for continuous improvement.

3. Continuous Improvement:

Unlike linear models, PDCA operates in a continuous loop. After the Act stage, the cycle repeats, allowing for ongoing refinement and optimization. This iterative nature ensures that improvements are sustained and built upon, leading to long-term growth and excellence.

4. Risk Mitigation:

By encouraging small-scale testing and careful analysis (Do and Check stages), PDCA helps in identifying and mitigating risks early in the process. This controlled approach minimizes the chances of large-scale failures and promotes a culture of thoughtful experimentation.

5. Enhanced Communication and Collaboration:

The clear structure of the PDCA cycle facilitates communication and collaboration within teams. Everyone knows the stage of the process and their role in it, leading to greater synergy and efficiency.

6. Problem-Solving and Innovation:

PDCA’s systematic approach encourages problem-solving and innovation. By continuously evaluating and adapting the plan, organizations can discover new solutions and approaches that may not have been apparent at the outset.

What are the four phases of the PDCA cycle?

The PDCA cycle has four key stages as can be seen in the graphic below.

Stage 1Plan – identify and define the problem, creating a plan for the change.

Stage 2 Do – Test the potential solutions from the plan.

Stage 3 Check – Study the results, analyze the results and understand what you have learnt.

Stage 4 Act – Take action based on the outcome of the previous step. If the change worked implement what was learnt from the test into the full process. If the change does not produce the required results repeat the cycle with a different plan.

PDCA Cycle


Within the planning stage, it is important to have a clear understanding of what the problem is you are trying to solve. Ensure those involved all have a clear and consistent understanding.

Once a consistent understanding has been established, you need to create a plan.

PDCA Planning

Within your plan is important to consider:

  • What are the goals?
  • How are we going to do it?
  • What resources do we need?
  • Who is responsible for taking action?
  • When are the actions going to be done?


Start implementing the plan as set out in the previous stage. Ensure everyone knows their role and responsibility, consider creating an effective communication plan for all stakeholders as changes to the process are likely and you need to ensure those involved understand what is happening and why.

You might find that the plan needs to adjust during this step as you implement your plan, therefore it is advised to start small and then expand once you are confident in the plan.


Review the results of the trial from the previous stage, did this produce the expected results?

Ensure you review the results with the team involved as they will be able to provide insight and understanding of the results based on their involvement.

Ensure you have collected sufficient data so that the test is statistically significant and not just a one-time result with may not be repeated.


Once everything has been tested and reviewed if the results meet the expected outcome it is time to implement the solution full-time into the process. Ensure all stakeholders are fully aware of what the change is and what they need to do to sustain the change. Tools such as Standard Operating Procedures (SOPs) or other training aid are useful in this step. During this stage it is useful to continue to check the process for a period of time after to ensure all issues have been resolved and that the problem does not reappear elsewhere.

Once this improvement is closed out you can repeat the cycle with further improvements to continually make improvements to the process.

If the results from the test do not meet the expected outcome return to the plan stage and repeat the process with a different potential solution.

When to use the PDCA cycle?

When an organization is looking to improve its processes or when a specific problem needs to be addressed, the PDCA cycle is frequently used. In this answer, we will go over when and how to use the PDCA cycle for project improvement.

  • When there is an issue or problem: The PDCA cycle is frequently used to solve problems or issues that an organisation may be experiencing. When a problem arises, the PDCA cycle can be used to identify the root cause of the problem, develop a solution, implement the solution, and then evaluate the results to determine if the problem has been solved. This can assist organisations in addressing issues quickly and effectively while minimising their impact on the business.
  • When continuous improvement is required: When an organisation wants to continuously improve its processes or products, the PDCA cycle is used. Organizations can use the PDCA cycle to identify areas for improvement, develop and implement a plan to address those areas, and then evaluate the results to see if the changes have resulted in an improvement. This can assist organisations in remaining competitive and meeting their customers’ changing needs.
  • When standardisation is required: The PDCA cycle can also be used to standardise processes within an organisation. Organizations can use the PDCA cycle to identify best practices, develop standard processes, implement those processes, and then evaluate the results to ensure that the processes are functioning as intended. This can assist organisations in increasing efficiency, reducing waste, and ensuring consistent quality.
  • When innovation is required: The PDCA cycle can also be used to drive innovation within an organisation. Organizations can use the PDCA cycle to generate new ideas, test those ideas, evaluate the results, and then implement the best ideas. This can assist organisations in staying ahead of the competition and discovering new ways to meet their customers’ needs.

The PDCA methodology is usually best suited to situations where the improvement needs a small amount of resouces and is a less intense problem. Whereas if these are greater you may consider A3, 8D, DMAIC or DFSS for your project.

Developing a culture of Continuous Improvement
Selecting a lean six sigma methodology

In conclusion, the PDCA cycle is a useful methodology for improving processes, products, and services within an organisation. It can be used in a variety of situations, including when there is a problem or issue, when continuous improvement is required, when standardisation is required, and when innovation is required. Organizations can use the PDCA cycle to quickly identify areas for improvement, develop and implement plans to address those areas, and then evaluate the results to ensure that the desired outcomes are met.


To summarise, the PDCA cycle is a valuable methodology for organisational continuous improvement. It is a straightforward approach that can be applied to small or simple change projects and is also known as the Deming cycle or Shewhart cycle. The PDCA cycle’s four stages: Plan, Do, Check, and Act, provide a logical sequence of steps for problem-solving. It enables controlled trials of potential solutions with adequate analysis prior to full implementation.

PDCA is useful for keeping the project team on track, facilitating communication, and keeping stakeholders focused. It is ideal for simple improvement projects that do not require extensive analysis. It is a powerful tool for organisations seeking to improve their efficiency and achieve continuous improvement.



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Daniel Croft

Daniel Croft is a seasoned continuous improvement manager with a Black Belt in Lean Six Sigma. With over 10 years of real-world application experience across diverse sectors, Daniel has a passion for optimizing processes and fostering a culture of efficiency. He's not just a practitioner but also an avid learner, constantly seeking to expand his knowledge. Outside of his professional life, Daniel has a keen Investing, statistics and knowledge-sharing, which led him to create the website learnleansigma.com, a platform dedicated to Lean Six Sigma and process improvement insights.

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