People construct models because they are
far simpler and cheaper to build and test quickly than the actual
thing being modeled. Most models are fairly special-purpose, and
omit details not relevant to this singular mission. Scale mock ups
are not good for showing electrical conduits and an air flow model
won’t help with the analysis of the structural integrity of the
building. However, by building such models we increase our chances
that the product to be constructed will actually meet the needs for
which it was commissioned.