That rather depends on what your aim is as a consulting firm and thus what you are trying to maximise for.For instance, annual growth could be a KPI if you are public consultancy or if you are looking to become public. If you are a partnership, high growth may in fact be a negative as it can destroy the culture and you have to add new partners and thus don't particularly increase the profit per partner (I know that Mck for instance is trying to limit its growth so as not to over-extend).If you care more about the health of the consulting firm rather than its direct performance (which I think is what many consulting firms should do) then you should look to indicators like staff attrition, staff satisfaction, %age of work that is coming from repeat work.