This is great
A good way of tracking those documents is encouraging regular use of a community wiki - one that is specific to that specific function-group. This is easier for us because by design our larger community is split into areas specific to certain functions (finance, hr, etc), meaning that it’s easy to capture useful documents. You would be able to track how many documents are uploaded, or with more work, how many people collaborated, how many requests for help were successfully answered (or a good attempt was made). That would be a good plug-in, a button that says whether a request or question has been answered to the asker’s satisfaction.
Do you have a good set of volunteers/moderators? A good idea is to get them to save/screengrab examples of positive interactions like this so that you can relate some actual stories on top of existing numbers (messages, average messages/posts per user, number of user generated discussions versus seeded, participation in regular weekly/monthly/etc community events).
I have found that most C- level supervisors want numbers/charts. I have found it to be useful to provide a smaller amount of criteria, shown visually, paired with notable examples of the behavior being tracked. This will help you demonstrate the value of the things you are tracking, and help you avoid having to bump simple traffic to increase that particular number.
I think it’s a common piece of knowledge here that there are far more useful numbers than simple visits, but you have to demonstrate the value of alternative metrics. For example, we are focusing on the engagement of existing members, which is a fraction of our total possible membership. That is working for now, but we are also tasked with demonstrating actual growth, or interactions that will lead to it, to keep everyone happy.
This involves a lot of compromise.
Is that helpful? Great question!