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Model for Improvement / PDSA

After using driver diagrams to discover what you want to change, the model for improvement is the approach, which will help you identify, carry out and evaluate the changes you make.

There are three questions every project team should ask:

1. What are we trying to accomplish?

  • Identify an area for improvement and use this to establish a specific aim – remember to be as SMART as possible (specific, measurable, achievable, realistic, and time-bound). For example; a patient falls reduction project might aim to ‘reduce patient falls on Ward A by 50% within six months.’
  • Determine what or who will be affected by this change
  • Give your project a deadline.
    NB. The aim may be the same as the aim in your Driver Diagram.

2. How will we know that a change is an improvement?

There are three types of measures:

  • Outcome measures, e.g. number of patient falls occurring
  • Process measures, e.g. reviewing the reliability of processes that may have an impact on the aim
  • Balancing measures to check unintended consequences, e.g. for a falls reduction project staffing levels may be a useful balancing measure.
    NB. The measures may be he same as those in your Driver Diagram.

3. What changes can we make that will result in improvement?

  • Get creative to develop ideas about how the improvement will be driven. Potential changes can be discovered using the driver diagram.
  • Remember, not all changes will result in an improvement. One change on its own may not achieve your aims.

Now time to PDSA

Plan, Do, Study, and Act is an effective method that helps teams plan the actions for their model, test it on a small scale, and review before deciding how to continue. It comprises four steps:


PDSA cycles are a fantastic way of taking ideas, trying them in practice, learning what works and what doesn’t to help you achieve success. You can broaden the scale of the test or adjust your ideas through more than one PDSA cycle – it may take a few before the idea starts to work reliably.


For guidance on how to use PDSA cycles effectively, see the information and video clips provided in the Resources section below.


Video clips