The role of statistical methodogies in the study or quality design of apparatuses and production systems

Up to the 60s the design criteria of industrial production systems were mainly based on the new findings achieved in that period in technical and physical environments and generally on techniques having deterministic nature. Examples can be typically found in the field of structural project that must support mechanic, dielectric and thermic stress. The functional forms of the relationship between stress (cause), strain and performance changes (effects) were supposed to be known using variables or parameters related to the size of the item under consideration. This kind of design enabled the collection and control of the unknown and random components by using the so-called safety coefficients. As a consequence of this approach, the existence of random effects in industrial work was ignored and a deterministic point of view was accepted.