Quality management: The Plan-do-check-act tool

The Plan-Do-Check-Act (PDCA) cycle, also called Plan-Do-Study-Act (PDSA), Deming Wheel or Deming Cycle, is a quality tool, a four-step continuous cycle to carry out improvement and change. This systematic approach helps businesses to think about what needs to change and then test it, in a continuous feedback loop, aiming to resolve problems.

The four phases are
identify and analyze the problem or opportunity, develop hypotheses about what can be changed and done and decide which one to test.
Do: test the chosen hypothesis, ideally on a small scale, and measure the results.
Check/Study: Study the results, measure the effectiveness of the changes made and decide whether the hypothesis is supported.
Act: If the solution was successful, implement it on the entire process/processes.

When to use a PDCA

Although a PDCA can improve any process or product, it is especially useful when:
Starting a new project, especially with repetitive work
Implementing a Total Quality Management or Six Sigma methodology
Developing a new or improved design, either for a product, service or process
Able to collect and analyze data


How to use a PDCA

1. Plan
Start by recognizing and understanding opportunity your problem or opportunity that you want to take advantage of.
Explore the information you have and try to think of ideas. Plan the change.

2. Do
Test the potential solution you identified. Preferably with a small-scale study, so you can assess whether the changes you planned to achieve the idealized outcome. Don’t forget to collect all the data you can.

3. Check
Review your pilot’s results against the expectations defined in Step 1. Understand if your idea worked or not.
Did it work? Proceed to step 4.
If it hasn’t worked, you must return to step 1, considering every lesson you got from this attempt.

In some cases you can decide to try more than one change and test more than one hypothesis, repeatedly going through Do-Check steps. You should move forward only when you feel pleased with the outcome of your experience.

4. Act
Implement your solution keeping in mind that PDCA is a loop, not a process with a beginning and an end. This means that you can and probably should keep on looking for improvements to your operation.

You are thinking about hiring a new supplier of zippers to use in one of your products. You decide to buy ten zippers and use it on your next order and receive great feedback from your client. As a result, you choose to use the new supplier to all your future orders of that product. This is a PDCA cycle, helping you continuously improving your business.


The PDCA pros

Simple and powerful tool
Allows you to test new solutions, improving your results
Can help you improve efficiency and productivity without risk, by testing changes on a small scale.


The PDCA cons

Can be a slow process, so not adequate for emergencies
It implies a culture of continuous improvement