Engineers in each branch apply their knowledge to many fields. Electrical engineers, for example, work in the medical, computer, missile guidance, or power distribution fields. Because complex problems cut across traditional fields, engineers in one field often work closely with specialists in scientific, other engineering, and career occupations. Often using calculators and computers to solve mathematical equations which describe how a machine, structure, or system operates, many engineers also use computer-aided design systems to produce and analyze designs. They also spend a great deal of time writing reports and consulting with other engineers.
Complex projects require many engineers, each working with a small part of the job.
Supervisory engineers are responsible for entire projects. Some engineers are at a desk in an office building almost all of the time but others work in research laboratories, industrial plants, or construction sites where they inspect, supervise, or solve on-site problems. Engineers in specialties such as civil engineering may work outdoors part of the time. A few engineers travel extensively to plants or construction sites. Employment Engineering is the second largest profession, exceeded only by teaching.