The most important thing to do when looking for a designer or engineer is to look for results. Design is one of the most important factors to consider when building a new product. Mechanical engineering is a branch of engineering that involves the application of physical laws and scientific principles to design, analyze, manufacture, and maintain mechanical systems. It is one of the oldest and broadest of the engineering disciplines. The mechanical engineering field requires an understanding of core areas including mechanics, kinematics, thermodynamics, materials science, structural analysis, and electricity.