  We discuss utilization of kinetic schemes for description of open interacting
systems, focusing on vibrational energy relaxation for an oscillator coupled to
a nonequilibirum electronic bath. Standard kinetic equations with constant rate
coefficients are obtained under the assumption of timescale separation between
system and bath, with the bath dynamics much faster than that of the system of
interest. This assumption may break down in certain limits and we show that
ignoring this may lead to qualitatively wrong predictions. Connection with more
general, nonequilibrium Green's function (NEGF) analysis, is demonstrated. Our
considerations are illustrated within generic molecular junction models with
electron-vibration coupling.
