Engineers also may specialize in one industry, such as motor vehicles, or in one field of technology, such as propulsion or guidance systems. Engineers in each branch have knowledge and training that can be applied to many fields. Electrical and electronics engineers, for example, work in the medical, computer, missile guidance, and power distribution fields. Because there are many separate problems to solve in a large engineering project, engineers in one field often work closely with specialists in scientific, other engineering, and business occupations. Engineers often use computers to simulate and test 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 major components or entire projects. Many engineers work in laboratories, industrial plants, or construction sites, where they inspect, supervise, or solve onsite problems. Others work in an office almost all of the time.