As a manager one of my key tasks is to identify who is ready for a promotion in the next promo cycle. My rule is simple: You are ready for promotion if you report to me and I have no fucking idea what you are doing. If we are that stage in our working relationship, then a) we both trust each other completely and b) you are largely autonomous and do not require me to make any decisions on your behalf. I trust your decisions and will back you. If both a) and b) are already true, this person should already be at the next level.