Wiring harnesses for complex assemblies, such as cars or airplanes, can contain hundreds or even thousands of wires. Routing all those wires from connector to connector is fraught with opportunities for error. One mistake can spoil an entire day of work.
The standard “technology” for assembling wire harnesses doesn’t do much to solve the problem. A full-scale 2D drawing of the harness is attached to a piece of plywood. Assorted clips and nails are then attached to the board at key locations on the drawing, such as ends and breakouts. Assemblers then manually route the wires from one point to the next like a giant game of connect the dots. Work instructions are often little more than a printout of the bill of materials.