Combining methods
Of note, different model-order reduction methods are not mutually
exclusive and a combination of one or more methods could be applied to
effectively reduce a model while exploiting the potential advantages of
each of the methods used. For example, Snowden et al. [29], used
proper lumping and balanced truncation to reduce two independent PBPK
and systems biology models, respectively, which were then combined into
a single simplified QSP model.