An open question in the field of non-equilibrium statistical physics is whether there exists a unique way through which non-equilibrium systems equilibrate irrespective of how far they are away from equilibrium. To answer this question we have generated non-equilibrium states of various types of systems by molecular dynamics simulation technique. We have used a statistical method called system identification technique to understand the dynamical process of equilibration in reduced dimensional space. In this paper, we have tried to establish that the process of equilibration is unique.