Abstract
The quality concept in an industrial sense was first seen in Japan after WW2. In a ruined country, American economists settled an action plan to rebuild the entire economy system.
Their first task was to define this notion. For Juran, "quality is the aptitude to employ" and For Crosby, "the reliability to specifications".
We can define this notion by three ways which match to different ages of Quality but which are its main basis. We must first underline the period after the WW2, and all the rebuilding needs, in Japan and in the rest of occidental countries. In that time, offer couldn't satisfy the population needs. In this way, products are sold very easily if they manage to roughly fit any targeted need. To satisfy a need with success, one must first define the product and its characteristics. A product linked to any need can't be sold! In the 70's and the well-known petroleum crisis the world had to face to an important plummeted consumption. The offer becoming higher than needs, products involved into something much more complicated with new functions.
