What factors do we need to consider in order to enable auto-growth settings for my PROD database
You've made an impressive start, here, starting to gather raw data that you can monetise and present to the business.  "This much data, this much cash each year".  

To make plans about data usage, you need to have an understanding of what's being stored in the database and, more importantly, how long your business should retain it (or, indeed, how long they're allowed to keep it).  

All too often, business people just want to keep everything.  "Disk space is cheap". 

That's fine, as long as they're prepared to put up the money for the extra disk space involved and for the overhead of [your] maintaining the table structures with things like Partitioning, to keep their Applications performing well. 

These days, however, there are additional, regulatory restrictions on how long data can be kept for and when it must be deleted at a User's request and, again, your business needs to come up with mechanisms for getting rid of data that they're no longer entitled to have or have been asked to delete. 

It's not something you can do on your own; you need to be working with your business to come up with the strategy together.