In the world of manufacturing, after design has made the drawings, and supply chain has purchased the parts, and the vendors have made the parts, there comes the first opportunity to build the assembly. In my ideal world, that happens with the technician who will build it every day, standing right beside the design engineer who invented it, and the manufacturing engineer who will make it easier to build, all three together building it. It's magical.
Why is it so cool? Well, there are often things about the design of the part that the design engineer will have to change. It's a very humbling time to be the design engineer, this thing you spent months on is happening in real time and when there are problem you are the only person to really answer most of the questions. It's also great because when the manufacturing engineer is right there, he or she can take notes and update the work instructions and maybe even the bill of materials in real time. By having a really good edit to the instructions during the first article build, future builds will go much more smoothly. Of course it's somewhat a never ending process, continuously improving the parts and instructions to make it go faster and have fewer issues. But the magic is the first time it happens. Everyone has a genuine curiosity about the process. And everyone becomes steeped in the details of the process, so that when future people are hired to learn how to do it, anyone that was there at the beginning has a wealth of knowledge about why things are done a certain way.
I've thought a lot the last few years about how to scale from one to ten, and ten to 100, and a little bit of thinking beyond that. If you only ever make one, for the most part the engineers who designed it can build it. But very quickly, somewhere between zero and five products, it's probably best to create documentation so that people skilled at building things, can build things, and people skilled at designing things, can design things.
Point being, the magic is the deep understanding of how the thing is built, and the ownership from everyone on the team to be there for all of the little successes and scary failures that inevitably occur in the process of building something new. It's so cool when it happens!