  Global models of planet formation tend to begin with an initial set of
planetary embryos for the sake simplicity. While this approach gives valuable
insights on the evolution of the initial embryos, the initial distribution
itself is a bold assumption. Limiting oneself to an initial distribution may
neglect essential physics that precedes, or follows said initial distribution.
We wish to investigate the effect of dynamic planetary embryo formation on the
formation of planetary systems. The presented framework begins with an initial
disk of gas, dust and pebbles. The disk evolution, the formation of
planetesimals and the formation of planetary embryos is modeled consistently.
Embryos then grow by pebble, planetesimal and eventually gas accretion. Planet
disk interactions and N-body dynamics with other simultaneously growing embryos
is included in the framework. We show that the formation of planets can occur
in multiple consecutive phases. Earlier generations grow massive by pebble
accretion but are subject to fast type I migration and thus accretion to the
star. The later generations of embryos that form grow to much smaller masses by
planetesimal accretion, as the amount of pebbles in the disk has vanished. The
formation history of planetary systems may be far more complex than an initial
distribution of embryos could reflect. The dynamic formation of planetary
embryos needs to be considered in global models of planet formation to allow
for a complete picture of the systems evolution.

Earth and Planetary Astrophysics