Developing consistent metric for Usage/Adoption across customer set

In my customer portfolio, I have customers that use our software in different ways.  Depending on how they are using it will dictate the type of usage I can expect.  I am trying to develop a consistent usage metric across my customer set so this can be an element of the overall health score.  I have thought about creating separate buckets of customers to group them into like categories, and then develop a separate usage metric for those buckets.  I am wondering if anyone has had to deal with something similar for other ideas.