Plan Do Study Act Cycle (PDSA)


Also known as: PDCA (plan-do-check-act) cycle. Deming cycle, Shewhart cycle

The PDSA cycle is a four step model providing a framework for developing, testing and implementing changes leading to quality improvement. Based in scientific method, the PDSA cycle moderates the impulse to take immediate action enabling services to instead test change on a small scale and build on the learning from test cycles in a structured way before fully implementing change. 


When can we use the PDSA cycle?

  • When starting a new Quality Improvement project
  • When implementing change 
  • When improving or developing a new design for a process or service
  • As a model for continuous improvement
  • When planning data collection in order to verify and prioritise problems or root causes  
  • It is essential to know what you want to achieve, how you will measure improvement and to be explicit about the idea to be tested.

Before entering the PDSA cycle, the framework requires you to start by answering three fundamental questions: 

  1. What are we trying to accomplish? ( the aim statement)
  2. How will we know that a change is an improvement? What measures of success will we use?
  3. What changes can we make that will result in an improvement?( the change concepts to be tested)

How do we use the PDSA cycle 

  1. Plan: After identifying an opportunity, then plan the change 
  2. Do: Carry out the test or change
  3. Study: Review the test or change, analyse the results and identify what you have learnt 
  4. Act: Take action based on the results from the study step; either the next change cycle or eventually full implementation. If the change did not work, then this is time to go through the cycle again with a different plan. Once the process is successful, now you can implement what was learnt during the test cycle. 
    Take what you have learnt from this to inform the planning for new improvements – the cycle now begins again.