Business Glossary

the use of a computer for designwork in fields such as engineering or architecture, with the computer's graphics capabilities substituting for work that traditionally would have been done with pencil and paper. In order to do CAD, it is necessary to have a high-resolution monitor and a software package designed for the purpose.

In order to draw a building, for example, it is necessary to enter the plans by using a graphical input device, such as a mouse or graphics tablet. There are several advantages to having the plans in the computer:

1. The computer can automatically calculate dimensions. In fact, the ability to calculate dimensions is the biggest difference between CAD programs and ordinary draw programs.
2. Changes can be made easily (e.g., adding a new wall).
3. Repetitive structures can be added easily.
4. The image can be enlarged to obtain a close-up view of a particular part, or it can be shrunk to make it possible to obtain an overall view. If the CAD program has three-dimensional capability, the image can be rotated to view it from many different perspectives. (See three-dimensional graphics ). For example, the Boeing 777 airplane, first rolled out in 1994, was designed entirely on computers. Previous airplanes had been designed the traditional way with paper drawings, and then a full-scale mock-up had to be constructed to make sure that the parts would fit together in reality as they did on paper. CAD made this extra work unnecessary.