This process applies to products as different as lawnmowers, computers, military weapons, and toys. In addition to design and development, many engineers work in testing, production, operations, or maintenance. They supervise production processes in factories, determine the causes of breakdowns and test newly manufactured products to maintain quality. They also estimate the time and cost to complete projects. Some work in engineering administration and management, or in sales where an engineering background enables them to discuss the technical aspects of a product and assist in planning its installation or use.
Some engineers work as consultants.
Within the major branches are numerous subdivisions. Structural, hydraulic, and highway engineering, for example, are subdivisions of civil engineering. 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 apply their knowledge to many fields. Electrical engineers, for example, work in the medical, computer, missile guidance, or power distribution fields.