I generally hear this about MBBs. Is the practice common across other/all consulting firms as well (like S&, ATK, RB..)?
Which are the consulting firms that practice up-or-out policy?
the up-or-out policy is still seen as the standard among board-level strategy consultancies. However, there are differences between some of the non-MBB firms and the strictness with which they apply it. For example, I know that Accenture Strategy and also Oliver Wyman are not really having an up-or-out culture in the strict sense. But if you want to know the specifics for any particular firm, I believe you have to talk to employees and/or alumni from this firm.
Don't forget also - even at MBB there are often ways to stay in the company even if you aren't approved to remain on the partner track. You can switch to the expert track for example, or even join the back office functions and remain your whole career. I have seen many very smart and talented people in these functions at BCG, with a successful career & real advancement opportunities. The work-life balance is often much better as well fwiw
It happens here and there but of course not as strict as at MBB companies. In most of the cases, it really depends on how your office / practice is doing. I've seen up or out cases even at Accenture in UK.