Imagine a product life cycle where you build one of the most expensive, complicated machines that humans can make, with a huge web of interrelated suppliers, an

Imagine a product life cycle where you build one of the most expensive, complicated machines that humans can make, with a huge web of interrelated suppliers, and specific skilled labour and knowledge. Now, imagine you only build one a year. And it takes like... 4 months to build one with a bare minimal crew. Now what? What do you do with all your expensive stuff? Maybe you can just build a whole bunch of them at once, and leave them stockpiled? But that's not very efficient is it? What if it turns out there's a major flaw that has to be corrected, or what if it turns out you're not needing as many rockets as you need? Maybe you can stretch out your production time more - but since 4 months is the longest 'efficient' time you can spend on a rocket, then you're just increasing your costs. Rocket (and airplane, and tank, and ships, and other expensive hardware things) production lines can't just spin up and spin down. This is why military procurement is partly so screwed up - because it's not really aimed at producing stuff at the best rate, it's aimed for the dual goal of getting Congressmen in office, and maintaining the manufacturing base for the future.