Once the Specifications Document is finalized, hardware design begins which realizes the system described. Depending on the intelligence and or autonomy of the system an integrated chip (IC) is selected to perform the functionality. ICs require secondary circuitry design in order to support their functionality: like a mother board of a desktop computer supporting the central processing unit. Hardware prototypes are designed with testable circuits to identify specification achievement, a milestone within the project.
Starting at the specifications stage of design a client may only require hardware prototypes with supporting documents.