A product's success or failure can be attributed to any element of it. Instead of testing the physical product, concept testing examines the idea behind it.
Somebody had a challenge or saw a challenge and believed that a machine could come in handy in solving the problem.
Consequently, they got to work and followed the mechanical engineering process that ended up with the production of the equipment.
They are subsequently able to help millions to billions of people around the world in solving their problem.
It is during the design stage that you are able to create a visible copy of what the product will look like after completion based on what you have in mind.
This stage is important since it is based on the look that the prototype can be developed.
Furthermore, most people also consider looks when buying a product.