What is the methodology used at robot companies to design and develop a new robot?

Hello,

My background is a MS in control theory, and from what I understand, the big industrial robot companies (Kuka, Fanuc, ABB, etc.) have large teams of engineers (controls, mech, elec, software, etc) working for many years on a design to bring it to a product-ready state. How correct is this?

Can someone who works/has worked at one of the big robot companies provide any insights into the methodology used?