U N I T 3 COMPUTERIZED DRAWING This Unit looks at the main characteristics and applications of computeraided design (CAD) and the various stages of its design process. It also gives information on computer-aided manufacturing (CAM) and its connection to CAD, in computer-integrated manufacturing systems. A. COMPUTER-AIDED DESIGN Drawing boards and manual drawing do not always provide precise and rapid results: traditional design practice may be rather slow and repetitive, especially in the product s design phase, when drawings are continuously revised, modified, analyzed and optimized. Today these modes of drawing and modelling have been widely replaced by computer-aided design (CAD): a computerized system which assists in the creation, modification, analysis and optimization of the design of a physical object. This technology is generally employed by engineers, graphic and product designers in the automotive, aerospatial and naval fields, but has applications in electronics, too. Originally the acronym CAD referred merely to Mechanical components automated drafting but now it also involves three-dimensional modelling and computer-simulated operation of the model. CAD drawing has remarkably enhanced designers efficiency and productivity: it is much faster and more accurate than traditional manual drafting; designs can be quickly modified, reproduced and transmitted electronically, thus improving and speeding up information exchange among the various components of the manufacturing process. The computer-simulated analysis of the model s behaviour under conditions of stress allows experts to visualize its potential problems and defects on the computer screen: alternative solutions can be rapidly found without building prototypes, thus saving money and time before product manufacturing. Most CAD systems today even analyze requirements for materials, tools and manufacturing methods. Once the design procedure has been completed, the CAD system can generate the detailed drawings required to start product manufacturing. GLOSSARY behaviour: comportamento to enhance: aumentare merely: solamente 196 once: una volta che, quando to optimize: ottimizzare requirement: requisito to save: risparmiare stress: sollecitazione thus: quindi, di conseguenza