  We characterise and study dynamical localisation of a finite interacting
quantum many-body system. We present explicit bounds on the disorder strength
required for the onset of localisation of the dynamics of arbitrary ensemble of
sites of the XYZ spin-1/2 model. We obtain these results using a novel form of
the fractional moment criterion, which we establish, together with a
generalisation of the self-avoiding walk representation of the system Green's
functions, called path-sums. These techniques are not specific to the XYZ model
and hold in a much more general setting. We further present bounds for two
observable quantities in the localised regime: the magnetisation of any
sublattice of the system as well as the linear magnetic response function of
the system. We confirm our results through numerical simulations.
