PDSA cycle

Also known as PDCA cycles

The Plan, Do, Study, Act (PDSA) cycle is a method for rapidly testing a change - by planning it, trying it, observing the results, and acting on what is learned. This is a scientific method used for action-oriented learning.

The PDSA Cycle

After changes are thoroughly tested, PDSA cycles can be used to implement or spread change.  The key principle behind the PDSA cycle is to test on a small scale and test quickly. The PDSA philosophy is to design a small test with limited impact that can be conducted quickly (days if not hours!) to work out unanticipated “bugs”.  Repeated rapid small tests and the learning’s gleaned build a process ready for implementation that is far more likely to succeed.

Video from IHI Open School Online Course (8 min)

Parts of the PDSA cycle

1. Plan – In this phase, your objectives are defined and your team makes predictions about what will happen, and why it will happen.  Your team will answer the following questions:

  • What exactly will you do?
  • Who will carry out the plan?
  • When will it take place?
  • Where?
  • What data/information will you collect to know whether there is an improvement?


2. Do – In this phase, your team will carry out the plan and collect the data.  This will include documenting experiences, problems, and surprises that occur during this test cycle.

3. Study – In this phase, your team will analyze the test cycle and reflect on what you have learned.  You will compare results with the predictions made in the planning stage, and draw conclusions based on the collected data.

4. Act - In this last phase, teams decide if there are any refinements or modifications needed to the change you have tried.  This may lead to additional test cycles, which starts the process all over again with Plan. 

Linking PDSA Cycles and Tests of Change 

Testing changes is an ongoing process: the completion of each Plan-Do-Study-Act (PDSA) cycle leads directly into the start of the next cycle.

A team learns from the test:

  • What worked?
  • what didn't work?
  • What should be kept, changed, or abandoned?

This new knowledge is used to plan the next test. The team continues linking tests in this way, refining the change until it is ready for broader implementation within the practice.

People are far more willing to test a change when they know that changes can and will be modified as needed. Linking small tests of change helps overcome an organization's natural resistance to change and ensures team buy-in.

 Tips for working with PDSAs:

• No PDSA is too small
• Plan multiple cycles for a test of change, and think a couple of cycles ahead
• You can achieve rapid results
• PDSA cycles help you learn from your work
• Anyone can use them in any area – improvement is nearly always a team endeavour
• Just do it! – what can we do by next Thursday?
• Keep it simple
• Remember that you will learn as much from things that don’t go well as well as those that do go well

Common traps:

People generally want to solve their problems with one change and they try to implement the whole change with one plan.  These are common pitfalls to avoid:

• Not reflecting on what you have done in order to learn from it
• Implementing changes without planning
• No testing, only data collection
• Undisciplined PDSAs – no documentation
• Thinking too big – beware cycles longer than 2 weeks.

Other quality improvement tools

Credits: EQUIPPED Long-term conditions collaborative, Auckland District Health Board.