Within skilled assembly, wire harnesses are perhaps the trickiest to get right, or at least the trickiest that we need a lot of, the trickiest without which nothing else turns on. So if you've been trained to heatseek bottlenecks at the system level and throw everything you've got at them until they're knocked out and you can move on to the next one, then wire harnessing is the logical place to start. And it turns out you can't automate it, yet.