The definition for new product development used on Wikipedia is “the transformation of a market opportunity into a product available for sale”, so the involved activities cover the complete process of bringing a new product to market.
The skills required for proper product development are therefore much broader than merely being a good designer and/or engineer. It takes critical elements from product and project management, technical and commercial. For example you must be able to understand the real needs of the client and user (often these are not the same), agree those with both parties and validate them quickly at low investment before you can proceed with concept design, advanced and detailed engineering.
During my career I have been involved in most of the steps and studied those I did not encounter. I am now confident that I can properly support any organisation with developing new products, especially those involving a human interface and mechanical systems.