Introduction to the PDCA-cycle: Plan, Do, Check, Act

PDCA stands for plan do check act and is also called sometimes plan do check to adjust or plan do study act. It is an iterative four-step method that can be used to continuously improve processes, products, and services. It also can be used to solve problems and implement changes.

The PDCA cycle is based on the scientific method where you create a hypothesis, design an experiment to confirm or negate the hypothesis and in the end, evaluate the results.

Iteration is key here. When using the scientific method  you use iteration to further extend your knowledge. When using PDCA cycles you are using iteration to further improve your processes, prodcuts and services.

The PDCA cycle is very easy to use scientific problem-solving technique and this makes it so popular. The PDCA cycle is particularly effective when you want to gradually improve in small steps. But as you know many small steps can have a big impact.


The first phase is the Planning phase. In the Planning phase we establish what we want to improve and which goals  we want to reach.

Do we want to solve a problem or improve a process?  If we want to solve a problem we have to describe clearly what the current problem is. For this, we can use several methods such as the 5W1H and is-is not method.

The other question we have to answer is when do we consider our improvement as successful. We have to define clearly how we are going to measure success. For this, we have to define a key process indicator and target.

Let's illustrate this with an example. Imagine that we are running a food delivery service. Customers are complaining that it takes too long before they get their food. In order to see if our improvements are successful, we could measure the time between when we receive the call and the customer gets his food. After a survey hold with our customer, we decide that less than 20 minutes would be the target. On the other hand, when the customer would complain that the food is cold when delivered we have another problem. In this case, we could use for example as Key Performance Indicator (KPI) the time between when the food is ready and when the food is delivered to the customer. As you can see understanding the problem and defining the correct KPI is key if you want to successfully solve a problem.

Most of the time, In order to solve a problem, you need a team of people. The people who will be part of the team are also defined in the planning phase. think carefully about who will be part of the team. You should try to get a multidisciplinary team. And do not forget the people who are closed to the process. The team will have to identify possible solutions, select the best solution and define the action to implement the selected solution. Often one of the actions is to collect extra information to make the right decisions. The solution selected should let us reach our goals when all actions are implemented.


The second phase is the do phase. In the do phase, we carry out the actions that are needed to reach the goals. If possible we have to run a pilot. A pilot is a preliminary trial where we implement the solution on a small scale in order to validate if the solution is viable. In order to check if the solution is viable, we will have to collect data during the trial. Once we are certain that we can reach our goals with the selected solution we can implement it on a full scale.

Doing a pilot has several benefits. It lowers the risks of failure, gives us the opportunity to assess the true performance of our solution under "real" conditions, and if needed gives us the opportunity to fine-tune the solution even further.  furthermore, it gives the opportunity to the stakeholders to give their feedback before the final implementation. this will decrease the risk of resistance to the proposed solution and increase the buy-in.


The third phase is the check phase. During the check phase, we analyze the collected data and compare the actual results against the planned goals.  In short, the effectiveness of the solutions is checked and further improvement can be discussed when needed.


Finally, The fourth phase is the Act phase. The phase has to make certain that the improvement is sustainable. If we detected in the check phase that the goals can not be met we have to look again at the process and adjust it. We will have to start the cycle again.  If the goals are made and we were able to run a pilot, we can implement the solution now on a full scale. We have to document the process and create standards so that the improvement will be sustained.

 By creating standards we create a basis from where we can start our next improvement.  By documenting your best practices in standards you reduce variation and make certain that the customer gets every time again the quality they expect.

Do not forget that we need to keep monitoring the process and react as soon as we see a deviation.

Remember, the PDCA method is an iterative method. Once you have completed your PDCA cycle you may want to define the next targets you want to reach and repeat the PDCA cycle again.

Having standards does not mean that you can not change the way of working. In fact, you should look at them as living documents which are updated after improving the current way of working. The “new” standards will form again the baseline for the next cycle of continuous improvement. After all continuous improvement is a never-ending story. We can take the lessons learned from one cycle to the next cycle.

This article was updated on November 30, 2022