  We present a model for the dynamical evolution of subhaloes based on an
approach combining numerical and analytical methods. Our method is based on
tracking subhaloes in an N-body simulation up to the last point that it can be
resolved, and applying an analytic prescription for its merger timescale that
takes dynamical friction and tidal disruption into account. When applied to
cosmological N-body simulations with mass resolutions that differ by two orders
of magnitude, the technique produces halo occupation distributions that agree
to within 3%.
