  Using numerical simulations, the onset of Poiseuille flow in a confined soft
glass is investigated. Starting from the quiescent state, steady flow sets in
at a time scale which increases with a decrease in applied forcing. At this
onset time scale, a rapid transition occurs via the simultaneous fluidization
of regions having different local stresses. In the absence of steady flow at
long times, creep is observed even in regions where the local stress is larger
than the bulk yielding threshold. Finally, we show that the time scale to
attain steady flow depends strongly on the history of the initial state.
