lil one, it seems that you answered your own question within the title of your thread, IMHO...

the station of a submissive, a SUBserviant, if you will...is to serve his/her Dom, to the satisfaction of both

i've done "tasks" (assignments given by Master for me to complete), i always try to be available to Him, when he wants/needs me and mostly to be there to satisfy His needs, whatever they be....