Stakeholder Analysis is a good starting point and without it, things can go horribly wrong with confusion and disengagement during development and as the changes are being implemented.

Even if you are at a stage where you are still define what the future looks like enough to be able to share an aim, understanding who will influence how the changes are made and how others will be impacted, gives you a clearer view of who to engage with and how throughout the process.

You can use a simple formats like the ones in the image on this page to help think through, capture and track information about your audiences.