Computer-aided design has come of age in the magnetic devices industry. From its early beginnings in the 1960s, when the precision needs of the experimental physics community first created a need for computational aids to magnet design, CAD software has grown to occupy an important spot in the industrial designer's tool kit. Numerous commercial CAD systems are now available for magnetics work, and many more software packages are used in-house by large industrial firms. While their capabilities vary, all these software systems share a very substantial common core of both methodology and objec­ tives. The present need, particularly in medium-sized and nonspecialist firms, is for an understanding of how to make effective use of these new and immensely powerful tools: what approximations are inherent in the methods, what quantities can be calculated, and how to relate the com­ puted results to the needs of the designer. These new analysis techniques profoundly affect the designer's approach to problems, since the analytic tools available exert a strong influence on the conceptual models people build, and these in turn dictate the manner in which they formulate prob­ lems. The impact of CAD is just beginning to be felt industrially, and the authors believe this is an early, but not too early, time to collect together some of the experience which has now accumulated among industrial and research users of magnetics analysis systems.