POSED BY MODEL. Computer-aided circuitry design. Man uses a computer to design electronic circuitry. On the computer monitor is a highly magnified plan of part of the circuitry which the designer can manipulate. Computer-aided design (CAD) is a crucial aspect of modern electronic engineering. It gives the designer the flexibility to make drastic alterations and calculate their effects immediately. Once the design plan is fixed the computer can generate master plans used to manufacture the circuitry.