Comment by GaelFG

I dont know if you are joking but when managing i do exactly that and that work (with a factor of 3 to be precise, with most people, some aldready take that into account). Works also with myself, i askmyself 'how much i think it will take, i double it and i assume half the day i will be bothered by other unplanned things'. It work remarkably well especially for longer projects.