  We present N-body simulations of planetary system formation in
thermally-evolving, viscous disc models. The simulations incorporate type I
migration (including corotation torques and their saturation), gap formation,
type II migration, gas accretion onto planetary cores, and gas disc dispersal
through photoevaporation. The aim is to examine whether or not the oligarchic
growth scenario, when combined with self-consistent disc models and up-to-date
prescriptions for disc-driven migration, can produce planetary systems similar
to those that have been observed.
  The results correlate with the initial disc mass. Low mass discs form
close-packed systems of terrestrial-mass planets and super-Earths. Higher mass
discs form multiple generations of planets, with masses in the range 10 < mp <
45M_Earth. These planets generally type I migrate into the inner disc, because
of corotation torque saturation, where they open gaps and type II migrate into
the central star. Occasionally, a final generation of low-to-intermediate mass
planets forms and survives due to gas disc dispersal. No surviving gas giants
were formed in our simulations. Analysis shows that these planets can only
survive migration if a core forms and experiences runaway gas accretion at
orbital radii r > 10 au prior to the onset of type II migration.
  We conclude that planet growth above masses mp > 10M_Earth during the gas
disc life time leads to corotation torque saturation and rapid inward
migration, preventing the formation and survival of gas giants. This result is
in contrast to the success in forming gas giant planets displayed by some
population synthesis models. This discrepancy arises, in part, because the type
II migration prescription adopted in the population synthesis models causes too
large a reduction in the migration speed when in the planet dominated regime.
