That's what I meant:

• The one with skill in design does the design.
• The one that can advise and test does the advising and testing.

The problem with a lot of stuff nowadays is that computers have taken away the requirement for skill.  But anyway, I doubt I'd ever produce a figure unless it was something I did in spare time at a relaxed pace.  But if it ever happend, I'd be sure to send it over to Vilters Testing Laboratories for some bulletproof testing before I decided to release it.