  A novel mechanism for the appearance of oriented processes is investigated
with a flexible dynamical system overcoming barriers. Under non-equilibrium
condition with external driving, reaction paths deviate from that at
equilibrium with an accompanying violation of symmetry between the forward and
the reverse paths. Although we never introduce any external switching of
potentials to generate the oriented processes, multi-dimensional flexible
dynamics promote the oriented processes through this symmetry violation. Along
the reaction paths, bottleneck points are proposed as a rate-controlling
factor, which determine the {\it direction-dependent activation energies}
satisfying Arrhenius-like law for the rate constants. In comparison, in stiff
systems, the oriented process is suggested to appear in different manner from
this scenario.
