Overview

Engineering design is a striving toward optimality, then, to minimize cost and to maximize function. In any particular situation, these needs may seem contradictory, but that is often an illusion. The most functional design can be the simplest; the optimal solution is usually the least expensive.Fundamentals of Mechanical Component Design, Edwards Jr & McKee^[1]

Machine

1. An apparatus consisting of interrelated units, or
2. A device that modifies force or motion.

“The interrelated parts referred to in the definition are also sometimes called machine elements in this context. The notion of useful work is basic to a machine's fucntion as there is almost always some energy transfer involved. The mention of forces and motion is also critical to our concerns as, in converting energy from one form to another, machines create motion and develop forces. It is the engineer's task to define and calculate those motions, forces, and changes in energy in order to determine the sizes, shapes, and materials needed for each of the interrelated parts in the machine. This is the essence of machine design.Machine Design, An Integrated Approach, Robert L. Norton^[2]