  We derive the fusion hierarchy of functional equations for critical A-D-E
lattice models related to, the sl(2) unitary minimal models, the parafermionic
models and the supersymmetric models of conformal field theory, and deduce the
related TBA functional equations. The derivation uses fusion projectors and
applies in the presence of all known integrable boundary conditions on the
torus and cylinder. The resulting TBA functional equations are_universal_ in
the sense that they depend only on the Coxeter number of the A-D-E graph and
are independent of the particular integrable boundary conditions. We conjecture
generally that TBA functional equations are universal for all integrable
lattice models associated with rational CFTs and their integrable
perturbations.

High Energy Physics - Theory