I tune production systems for a living and have been doing this for about 20 years now. There are exceptionally few companies out there that have a test platform that even remotely resembles their production hardware, and many don't even restore their main (often VERY large) databases down to a test server very often either for many reasons. Yes, you have to be careful and take steps to measure impact and minimize the probability that something is adversely affected. Yes, you have to set managements' expectations and understandings that something bad could happen. Yes, you do have to be much more competent so you know how to better judge if something you want to do for tuning will make other stuff worse.