What is a sketch? We started off with asking everyone to draw a sketch of one of the following things in 60 seconds: taxi, bike, cow, or door. It was apparent good sketches focus on the key essensentials. We adapated the Merriam-Webster definition of a sketch to a hardware sketch.
Definition: Hardware Sketch
A rough functional system representing the chief features of a smart object, device or environment and often made as a preliminary demonstration of the idea and functionality.
Some advantage of sketching are the fast iteration of ideas and the value in communication. This is true for hardware skectches, too.