I found a good writing about the complexity of an opera backstage activity which runs all around the clock 24/6 or even 24/7. Found it via artsjournal.com written by Judith Dobrzynski.
Big opera house with a lot of production needs one superb team to coordinate all the things happening in an opera, of course besides the music itself. Over-the-edge machines, backdrops, properties, lighting, set, makeups, costume, which some of the time, need several containers to bring to the opera house from warehouses outside of town.
The fuzz and buzz of Metropolitan Opera’s “Götterdämmerung” can be found here, Great Performances — Behind the Scene.