The discussion above has shown the implications -- summarized in Table 6.1 -- that result from the two extremes of parallelization strategies. It is clear that bottom-level parallelization should only be applied where it really makes sense and no other alternative is available. The discussion also points out the potential which parallelization on a high level offers for most of the simulation problems arising from TCAD investigations. Despite of this, few implementations which explore this field exist [53,62]. All considerations will focus on parallelization at the top-level in the remaining of this chapter.