  A general method for computing derivatives of solution fields and other
simulation outputs, with respect to arbitrary input quantities, is proposed.
The method of automatic differentiation is used to carry out differentiation
and propagate derivatives through the simulation code by chain rule, in forward
order. An object-oriented approach using the operator overloading and
templating features of the C++ programming language is presented. Verification
results are given for a plane wall with surface convection, where the
derivative of the dimensionless temperature field with respect to the Biot
number is computed and compared to an analytical solution. Further results are
given for conduction in a composite material with regions of different thermal
conductivity. The derivative of the temperature field is computed with respect
to the conductivity of one of the phases using the proposed method.
