"yetkinlik" is a problematic term, as you must have realized, too. in daily speech it might be used to mean "perfection", if it's used at all, also dictionaries define it as such; in a management context it might as well mean "qualification" as suggested in your other and related question, but i feel there must be more to it (you get qualified as a translator first, that is you learn to translate and get licensed, and then work to improve your skills toward perfection), so maybe the one above or

perfection-oriented integrated management approach

would work better.