The diffusion modeling framework PROMIS-NT has been built on top of the basic input/output, equation solving and transient time step control modules of the diffusion simulator DIFFUS. Therefore the discretization function of a number of built-in diffusion models were replaced by the discretization functions for the differential equation systems (4.1) - (4.8). Interface structures to the Algorithm Library have been introduced within these discretization functions as well as for the initialization and post-processing of quantities, the process temperatures modeling, quantity definition and other strategic algorithms for the diffusion modeling. A set of PROMIS-NT specific MDL Parameter classes, operators, functions, and Model classes forms the development platform for user defined diffusion models collected in external libraries of MDL extension libraries and MDL input decks (Fig. 4.2).
