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Driver Diagram

Driver diagrams are a type of structured logic chart with three or more levels (see example below).

These include:

  • a goal or vision
  • the high-level factors that you need to influence in order to achieve this goal (called ‘primary drivers’)
  • specific projects and activities that would act upon these factors.

For more complex goals the number of levels in a driver diagram can be expanded so that each primary driver has its own set of underpinning factors (i.e. ‘secondary drivers’ etc.). It is these secondary drivers (or lower level drivers) that would then be linked to projects and activities.

Driver diagrams provide a ‘theory of change’. An example of a driver diagram is shown below.


Driver diagrams can fulfil a range of functions. They can:

  • help a team to explore the factors that they believe need to be addressed in order to achieve a specific overall goal
  • show how the factors are connected
  • act as a communication tool for explaining a change strategy
  • provide the basis for a measurement framework.

Driver diagrams are therefore best used when an improvement team needs to come together to determine the range of actions they have to undertake to achieve a goal.

Four steps for a successful driver diagram

  1. Set out what you want to achieve in your Aim. Make it specific and measurable. It should not simply be ‘to reduce’ or ‘to improve’. It should be meaningful to staff, patients, and families. A key benefit of a well-written Aim is that it can help you to identify your outcome Measure (see Measurement for Improvement).
  2. Identify the big topics and important areas that need to be addressed to achieve your aim in the Primary Drivers, such as Patient Choice. Well-written Primary Drivers help you identify your process measures, which review the reliability of processes that might have an impact on the aim of the project.
  3. Consider which activities can positively influence the Primary Drivers. In the case of Patient Choice it might be complaints or a ward round. These are Secondary Drivers, which can influence more than one Primary Driver and help you identify relevant Change Ideas.
  4. Think very carefully about your Change Ideas. They should have an effect on at least one Secondary Driver and help achieve your aim. These are the important changes that will go into your project plan.

Driver diagrams fit into an improvement process. Before starting a driver diagram it is important to be clear about your goal. These goals are also termed ‘aim statements’.

Once you have a completed driver diagram (including identifying your projects) you are ready to begin project implementation. Driver diagrams therefore naturally lead into activities such as developing project plans and undertaking PDSA cycles.

Where drivers are defined measurably and the driver diagram is used as a measurement framework for monitoring progress, time-series techniques such as statistical process control (SPC) can be applied. More information is in the Measurement for Improvement section.


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