PDCA Cycle Explained: 4 Steps for Continuous Learning and Improvement

The Meaning of PDCA Cycle

PDCA Cycle (also known as PDSA Cycle or Deming Cycle), is a problem-solving method used for the continuous learning and improvement of a process or product. 

There are 4 basic steps in PDCA Cycle:

  • Plan: identify a problem and possible solutions
  • Do: execute the plan and test the solution(s)
  • Check: evaluate the results and lessons learned
  • Act: improve the plan/process for better solutions

These four steps incorporate inductive-deductive interplay and have been a simple and scientific approach for problem-solving (process-improving). It follows the curve of how we acquire knowledge through constant reflection, standardization, and modification.

The PDCA framework begins with a planning phase where a problem or a process to be improved is identified. This involves not only the goal setting and finding possible solutions, but also hypothesizing methods that can be used to reach the ultimate goal. Another thing that needs special attention is defining the success metrics. This simply means a clear evaluation matrix is ideally to be set beforehand.

Then, the solution(s) will be tested in the Do process. To detach the Do, there could be two steps: making the Do multiple To-Dos by splitting the task and defining them with a specific time, personnel, and steps, and collecting real-time data and feedback. 

Check includes analyzing the results and comparing them to the hypothesis in the Plan stage: how well the solution worked, how much the goal has been achieved, and whether the methods were proven feasible. If there are any unexpected issues, you may also need to find the causes and possible solutions. Note that there might be forth and back between Do and check.

The Act step closes the cycle, which involves adjustment on the initial goal or solutions and integration of all key learnings by the entire process, to standardize successful parts and avoid error recurrence. In a nutshell, the Act phase summarizes the current cycle and prepares for the next.

However, the PDCA cycle doesn’t stop here. Instead, it can repeat from the beginning with a modified version of the Plan. There is no end to it and sustainability should be its main pitch.

How PDCA Has Evolved

Usually used interchangeably with “PDSA Cycle”, “Deming Cycle”, “Deming wheel”, “Shewhart Cycle” etc, the PDCA model has indeed confronted some misunderstanding and confusion. It remains unexplained in most cases how PDCA became what it is today and what’s the difference between those mysterious terminologies and how they interact. According to Ronald D. Moen & Clifford L. Norman, its evolution could be summarized like the following:

Shewhart cycle (1939): Specification - Production - Inspection

He brought up this method from the viewpoint of Quality Control.

Deming Wheel (1950): Design the product - Make the product - Sell it - Test it.

Deming built off the Shewhart cycle and emphasized the four steps should be rotated constantly to aim for the product quality. This has gained increasing popularity when Deming participated in the Japanese Union of Scientists and Engineers (JUSE).

PDCA Cycle (the 1950s):  Plan - Do - Check - Act.

A Japanese executive reworked the Deming Wheel and translated it into the PDCA Cycle for problem-solving. PDCA emphasizes more on the establishment of standards during the process and the ongoing modification of those standards. 

Extended PDCA Cycle (1985): Plan - Do - Check - Act.

Kaoru Ishikawa refined the PDCA model to include more steps in the Plan and Do steps: Identify the goals and methods to use; involve in training and education during implementation.

PDSA Cycle (1985): Plan - Do - Study - Act.

Deming claimed that the ownership of PDCA Cycle was never recognized by anyone and the word “check” was used incorrectly because it means “to hold back”. Therefore, he replaced it with “study” to emphasize the importance of the continuous learning-improvement model.

How to Implement - PDCA Examples

Now, you’ve got a clear idea of what the PDCA Cycle is and how it changes over time. As a simple and structured method widely adopted in Quality Control and Total Quality Management, can it also be applied in wider areas, such as personal growth and business development? Yes, I’ll give you a couple of examples.

PDCA example
PDCA Cycle example

Benefits of PDCA Cycle

Among all those other methods, why does the PDCA model shade some lights in the history, especially known for the “Japanese Quality” and is still widely used today? Some key benefits of it need to be valued.

PDCA methodology emphasizes minimizing errors and maximizing outcomes. When applied to business development, e.g. a product’s iterations, it could ensure a developing path where the product is shaped better and better to the market and customers. It’s the same when it comes to personal growth. It also leaves space for constant check and reflection, which can avoid wasting time on the mistakes or making the same mistakes.

PDCA framework follows a learning curve and enhances the learning-improvement process continually. This is the key factor defining PDCA as a scientific and methodical way to gain knowledge. With knowledge building up, people’s ability goes up. 

PDCA model encourages a growth mindset. Seeing continuous improvements is a good way to enhance individuals’ self-esteem levels and bring a great sense of accomplishment. People tend to find meaning in the things they do. Imagine if one stops making progress, they would stay in the static and lose meaning in repetitive work and life. 


  • PDCA Cycle is a simple and scientific way for problem-solving and process improvement.
  • PDCA Cycle involves four key steps: Plan, Do, Check and Act.
  • PDCA works slightly differently from Deming Cycle, Shewhart Cycle, and PDSA.
  • PDCA Cycle is a never-ending process that can be used on a continual basis.
  • PDCA Cycle can be used for quality control, business development, and personal growth.