What is the PDCA Cycle

Guide: PDCA Cycle

The PDCA cycle, standing for Plan-Do-Check-Act, is a four-step management method used for continuous improvement of processes and products. It encourages systematic problem solving and iterative optimization.
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Daniel Croft

Daniel Croft is an experienced continuous improvement manager with a Lean Six Sigma Black Belt and a Bachelor's degree in Business Management. With more than ten years of experience applying his skills across various industries, Daniel specializes in optimizing processes and improving efficiency. His approach combines practical experience with a deep understanding of business fundamentals to drive meaningful change.

The PDCA Cycle, standing for Plan-Do-Check-Act, is a robust framework that has underpinned continuous improvement initiatives across industries for nearly a century. Developed by statistician Walter A. Shewhart and later refined and popularized by W. Edwards Deming, this iterative method fosters a culture of quality and efficiency. By methodically following its four stages: Plan, Do, Check, Act businesses can progressively refine processes, enhance products, and elevate operational performance. The cycle’s elegance lies in its simplicity and adaptability, making it suitable for a wide array of projects from process enhancement to product development.

Table of Contents

What is the PDCA Cycle?

The PDCA Cycle is a methodical approach used in continuous improvement businesses. PDCA stands for the steps in the method, which are Plan, Do, Check and Act (sometimes called Adjust).

The PDCA cycle was originally developed by A. Shewhart who was a statistician at Bell Telephone Laboratories. Shewhart was known as a pioneer in the field of quality management and is also referred to as the father of statistical quality control. He developed the concept of the PDCA cycle in the 1920s as a model for continuous improvement, emphasizing the importance of using data to make informed decisions.

Following this the model gained traction when W. Edwards Deming expanded on Shewhart’s ideas, popularized the PDCA cycle, and also started to be known as the Deming Cycle. Deming was an American engineer, statistician, and management consultant who worked in Japan following World War 2. Deming’s success is attributed to his teachings on the PDCA cycle in Japan and the use of PDCA in Japanese manufacturing.

The Four stages of PDCA:

  1. Plan: Identify an opportunity and plan for change.
  2. Do: Implement the change on a small scale.
  3. Check: Review the test, analyzing its success or failure.
  4. Act: If the change is successful, implement it on a wider scale.
The PDCA - Plan, Do, Check, Act Cycle

What types of projects can PDCA be used for?

The PDCA cycle is quite versatile and can be applied in a range of projects, particularly those that involve:

  • Process improvement: Projects which are looking to streamline processes, reduce waste or improve efficiency
  • Product Development: PDCA can be useful when developing new products. The cycle is particularly useful when doing interactive testing and quality enhancement to products.
  • Quality Management: In line with the original development the PDCA cycle is well-suited to improving the quality of products or services.
  • Operational Changes: The PDCA cycle can be used to implement new procedures or changes in workflow.

In general, for Lean Six Sigma the PDCA cycle is more ideal for small projects that lack complexity and dont need to be broken down into smaller steps like DMAIC, 8D and A3 offer. PDCA projects are usually used where smaller teams can address the problem. 


The Components of PDCA and How to Apply it

The PDCA Cycle is a four-step systematic method used to continually improve processes and products. Let’s look into the four components in more detail


The planning phase is about setting the foundations of what you want to achieve and creating the road map of how to get there.

Within this stage, you will generally do the following:

  • Identify Objectives: Clearly define what you intend to improve and objectives are usually SMART targets.
  • Analyze Data: Collect and analyze data to understand the current state of the process or product. This would usually involve qualitative or quantitative data, ranging from customer feedback to performance metrics.
  • Developing a Hypothesis: Based on the data analysis, a hypothesis will be developed about what changes could improve the process.


The next step is the Do phase; this is where the plan is put into action. This should be done cautiously to limit disruptions in case the plan does not have the expected results. 

Within this stage, you will generally do the following:

  • Small-Scale Testing: Implement the planned change on a small scale, limiting the impact of potential issues and risks. Often referred to as a pilot program or trial.
  • Data Collection: Collecting data during the pilot to analyze the results of the test in the next phase
  • Documentation: Document everything during the Do phase, including the process, any deviations from the plan, observations, and all data collected; these will be analyzed in the Check phase


This phase is where you review the data collected during the trial and determine if the changes made led to an improvement.

Within this stage, you will generally do the following:

  • Analyze the results: Analyze the data collected in the Do phase; this could include the use of statistical tools, if appropriate, to determine if the changes made a significant enough difference.
  • Compare: Evaluate the results against the objectives that were set during the Plan phase and determine if the hypothesis was correct and the results were met.
  • Conclude: Form a conclusion from the analysis. If the results are positive, proceed to the Act phase; if not, aim to understand why and what can be done differently.


Based on the results of the Check phase, you will take action.

Within this stage, you will generally do the following:

  • Implement: if the Check phase confirms the success of the Plan the new process should be implemented on a full scale. This could involve updating operating procedures, retraining staff, or upscaling the pilot program.
  • Standardize: To standardize and sustain the successful change you should update the documentation of the process to ensure consistency across the business.
  • Iterate: As always with continuous improvement, it does not stop with the clues in the title. Whether the change was successful or not, the cycle begins again. If it is successful, you start looking for the next opportunity to improve. If the change was not successful, you need to review and refine the plan based on what you learned through the cycle and apply it again.


The PDCA Cycle is a good example of the power of iterative learning and improvement. From its inception by Shewhart to its widespread adoption due to Deming’s advocacy, it has become a key tool of operational excellence.

Through careful planning, disciplined execution, rigorous checking, and decisive action, PDCA enables organizations to drive change effectively and sustain improvements. Its cyclical nature ensures that continuous improvement is not a one-time event but a perpetual journey, always seeking the next enhancement. Whether for small-scale changes or significant transformations, PDCA stands as a useful tool in Lean Six Sigma methodologies, guiding teams toward higher standards of quality and efficiency.


Additional Useful Information on PDCA

PDCA and Its Variations

  • PDSA: Some organizations use a slightly different version known as PDSA, which stands for Plan, Do, Study, Act. The “Study” phase encourages a more in-depth analysis than a simple “Check,” emphasizing learning from the outcomes.

  • OPDCA: Another variation includes an additional step—Observe. This five-step model (Observe, Plan, Do, Check, Act) places emphasis on observing the current state before planning changes, offering a more comprehensive overview of the situation.

Why Variations Matter

  1. Context-Specific: Different variations may be more suitable depending on the complexity and nature of the process you are aiming to improve.

  2. Enhanced Focus: Additional steps like “Observe” or “Study” can provide deeper insights and a more nuanced understanding of the process.

Integration with Other Tools

PDCA can be seamlessly integrated with other continuous improvement frameworks and methodologies such as:

  1. Lean Six Sigma: PDCA can be used within the DMAIC model as a tool for iterative testing and validation during the Improve phase.

  2. Kaizen: Kaizen events often use the PDCA cycle to test and implement quick, incremental changes.

A: PDCA stands for Plan-Do-Check-Act, which is a four-step iterative management method used for continuous improvement.

A: The purpose of PDCA is to systematically identify and solve problems, make improvements, and achieve better results in various processes and systems.

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A: The Plan phase is crucial as it involves setting clear objectives, defining the problem to be addressed, and developing a detailed plan to achieve the desired results. It lays the foundation for the entire PDCA cycle.


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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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