  Silicon radiation detectors are an integral component of current and planned
collider experiments in high energy physics. Simulations of these detectors are
essential for deciding operational configurations, for performing precise data
analysis, and for developing future detectors. In this white paper, we briefly
review the existing tools and discuss challenges for the future that will
require research and development to be able to cope with the foreseen extreme
radiation environments of the High Luminosity runs of the Large Hadron Collider
and future hadron colliders like FCC-hh and SPPC.
