Computers have become an integral part of the design engineer's job. Using CAD systems, engineers create realistic geometric models of objects on a computer terminal screen. They can rotate these images to view them from any desired angle, and even simulate and analyze the effects of different operating conditions and try out alternative designs. Computer-models are eliminating the need for handmade drawings and experimental physical prototypes. Testing of products in order to verify or improve their quality is an integral part of both design and manufacturing.
Test engineers select or develop the testing apparatus and procedures to be used.
If problems arise during testing, or if the product does not perform according to specifications, test engineers may recommend changes in overall design, in particular components or materials, or in certain manufacturing procedures. Engineers must be able to design, install and operate complex manufacturing systems made up of people, materials, robotics and other automated equipment. Along with this, they develop and monitor preventive maintenance programs. Sales of sophisticated technical products frequently require knowledge of how the device or system operates. Therefore, Mechanical Engineers are sometimes employed as sales representatives.