The general types of boundary models such as Neumann boundaries or Cauchy boundaries are managed in the same way as standard volume models. The difference the model developer has to keep in mind, is the reduced dimensionality of a boundary element in a higher order of space. Thus a model developed in the one-dimensional space can not just be copied for usage as a boundary model for two-dimensional problems because the points of the extracted boundary interfaces are defined in the two-dimensional space. Therefore the discretization of the model differs slightly from the one-dimensional case. Fortunately, the basic implementation of a boundary model does not make any difference to the standard volume model. Again, the residual vector and the Jacobian matrix must be defined by the model developer. Using the Input & Control Interface the boundary model can be mapped onto a definite boundary. During the simulation process AMIGOS evaluates the analytical boundary model and writes the calculated values to the global stiffness matrix that has to be solved finally.