[not an expert so I could be totally wrong] I was also just talking about the physical space. Even if the machines on the entire line have to be replaced it still probably makes sense for a company to transition in situ - displacing the old line. There's the lease for the land and building, people's commutes are structured around a certain physical location, air conditioning and electricity are already there, etc... It's not just the big expensive machines that make up the fabrication - it's also the entire structure that makes that production happen.