theoretically it is possible, but if it amounts to "a working week" - ie - 40 hours, dont forget you are expected to do the equivalent of that in at home study. I do a 28 hour week at uni, and with 15 hours a week travel, plus 10 hours of casual work, theres no possible way i could fit in a tafe course too, coz of the amount of work to do for assignments and stuff, especially around exam time, it would be way too much.
maybe if your course was, say 15 hours or so a week, and depending on whether u have to work on weekends and stuff you could probably cope with it