Model for Improvement
& PDSA Cycles

Numerous improvement methodologies are used nationally and internationally, to improve processes of care or patient outcomes. Clinical Practice Improvement (CPI) is a commonly used methodology to address identified problems in the clinical area. It involves identifying, defining and diagnosing a problem, before developing solutions and implementing interventions that may address the identified issues. Possible solutions are then tested using small-cycle testing called "Plan, Do, Study, Act" (PDSA) cycles. [1],[2]

It is important to measure the impact of changes in order to verify that your interventions have made a difference. PDSA cycles were originally known as the Shewhart cycle, "Plan, Do, Check, Act", and based on manufacturing models. They were later modified by Edwards Deming to PDSA cycles.[3]

There are three main concepts to consider when undertaking improvement. This is demonstrated well with the Model for Improvement below. [1],[2] This model was developed by Associates for Process Improvement and is used by the Institute for Healthcare Improvement (IHI) as their framework to guide improvement work.[4]

Figure 1: Model for Improvement & PDSA (image adapted [2])

To learn more about the Model for Improvement and PDSA cycles, please refer to the Institute for Healthcare Improvement website. You may need to take a moment and register with the IHI for more in-depth information.

Video Links (IHI)


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[1] Nolan T, Resar R, Haraden C, Griffi n FA. Improving the Reliability of Health Care. IHI Innovation Series white paper. 2004; Boston: Institute for Healthcare Improvement. Available from:
[2] Langley GJ, Moen RD, Nolan KM, Nolan TW, Norman CL, Provost LP. The Improvement Guide: A Practical Approach to Enhancing Organizational Performance 2009.
[3] Moen RD, Norman CL. Circling Back: Clearing up myths about the Deming cycle and seeing how it keeps evolving. Quality Progress. American Society for Quality, November, 2010 Available from:
[4] How to Improve [internet]. Cambridge MA: Institute for Healthcare Improvement; 2016. Available from: