Quality is central to our lives. When we buy a car, when we choose a destination, when we go for an exhibition, or when looking for a restaurant the question of quality always plays a central role. However, if we were asked what quality is, each of us would have an idea of what quality usually different from the one of other people. Ideas diverge even more from language to language, from country to country, from tradition to tradition, from profession to profession, and so forth.
So, what is quality? To try and regulate this apparently irresolvable issue, the International Organization for Standardization (ISO) defines QUALITY as the “degree to which a set of inherent characteristics fulfills requirements”, in which “requirements” are “needs and expectations”.