ABSTRACT
T HE discipline of human factors exists because humans make errors in using machines; otherwise, it would be difficult to justify the discipline’s
existence. Since the terms humanfactors, ergonomics, humanfactors engineer ing, and human engineering have appeared interchangeably in the published literature, here human engineering is defined: a discipline that deals with de signing manmade objects (machines/equipments) so that involved individuals can use them safely and in an effective manner to create environments ideal for the living and working of human beings [1]. Usually, the term ergonomics is less often used in North America than the other three terms. It is derived from two Greek words: ergon (meaning work) and nomos (meaning law).
