Nah, I have no idea. Could be one, could be several, always depending on company approach. I have a master in engineering design, but my field of work has been rather large mechanical construction and automotive more recently. I've seen small parts for cars being designed by several people and a complete press being designed by mainly one guy (with 2 others just doing the drawings) so anything goes. But I might ask next time.
10/24/16 at 7:52am