Refining aim and change theory

The project team should use the learning from understanding the current system to refine the project aim. When refining the aim, the project team should consider what "better" looks like and what parts of the current outpatient pathway may be a high priority to change first.

Ideally the aim will become more specific but it could also change the timescale and/or the numeric element of the aim too. Any changes should be updated in the project charter.


Driver diagram

The driver diagram below outlines the change theory that will help the project team achieve the aim. 

A customisable version of the driver diagram has been created to allow services to adapt and include their own aim statement.  More information on driver diagrams can be found on the QI zone.


Measurement plan

Data is needed to help you determine if the changes you are making are resulting in improvement as outlined in the driver diagram.  The measurement plan outlines the measures that will help to use while testing changes. The data collection template will help you collect and present your data. 

The three types of measures are:

  • Process measures are related to the primary drivers of the driver diagram. These are the things that have to happen reliably to achieve the desired outcome
  • Outcome measures are related to the aim statement and demonstrate the impact of your changes, and 
  • Balancing measures are used to determine if your changes are having an impact elsewhere in your system.

More information about and using measurement for improvement can be found in the QI Zone.


Your theory of change

Please get in touch if you have customised the driver diagram or measurement plan to better meet your local situation.  Contact us through the feedback form or by emailing us at