Were looking at the maturity of the first steps of a technology that will
evolve into the SF/Star Trek 'Replicator' that generates spare parts on
demand, all info stored in digital form.  Think of it this way.  Our grand
children (maybe even our children) will bring up a part on the ETKA for
their vehicle (car, bus, airplane, etc) and hit 'Print' and a few minutes
later out pops the desired part.  No spares to carry on the Navy ships of
the future, no machine shop with lathe and mill, just the Replicator.