Unless growth is controlled, you'll lose money faster, experience increased turnover and suffer through quality-control issues. The formula for that seems to be five employees per principal or senior manager. Here are some signs to watch for. Responsibility for keeping projects on budget is not centralized. You guess at your fixed monthly overhead, and it's quite a bit higher than your guess.
Employees leave, complaining of the lack of structure and job descriptions.
There is no time to put things in writing. Let's just look at this last one in greater depth. The last time you left on vacation, we can assume that you tied up all those loose ends and then addressed in writing what might come up while you were gone. You were motivated to do this because you didn't want to be bothered. Despite protestations to the contrary, it has little to do with insufficient time to write everything down.