Based upon evidence such as already presented, it appears feasible to set up criteria by which to determine when assignable causes of variation in quality have been eliminated so that the product may then be considered to be controlled within limits. This state of control appears to be, in general, a kind of limit to which we may expect to go economically in finding and removing causes of variability without changing a major portion of the manufacturing process as, for example, would be involved in the substitution of new materials or designs.
Walter A. ShewhartRelated topics
changing control criterion example expect general kind manufacturing quality set state substitution variability variationRelated quotes
In my own household, for example, an electric refrigerator has been in service for nineteen years, with only a single minor repair: an admirable job. Both automatic refrigerators for daily use and deepfreeze preservation are inventions of permanent value. Though one cannot bestow any such unqualified commendation upon the design of the contemporary motor car, one can hardly doubt that if biotechnic criteria were heeded, rather than those of market analysts and fashion experts, an equally good product might come forth from Detroit, with an equally long prospect of continued use.
Lewis Mumford
The new trade theory picture of the world looks something like this: Each country has, at any given time, a set of broad resources-land, skilled labor, capital, climate, general technological competence. These resources define up to a point the industries in which the country can hope to be competitive on world markets. [...] But a country's resources do not fully determine what it produces, because the detailed pattern of advantage reflects the self-reinforcing virtuous circles, set in motion by the vagaries of history.
Paul Krugman
Evolution must have involved the simultaneous change in many genes, which doubtless accounts for its slowness. Here matters would have been easier if heritable variations really formed a continuum, as Darwin apparently thought, i.e. if there were no limit to the possible smallness of a variation. But this is clearly not the case when we are considering meristic characters. ...the atomic nature of Mendelian inheritance suggests very strongly that even where variation is apparently continuous this appearance is deceptive.
J. B. S. Haldane
The following work is not a republication of a former treatise by the Author, entitled, "The Mathematical Analysis of Logic." Its earlier portion is indeed devoted to the same object, and it begins by establishing the same system of fundamental laws, but its methods are more general, and its range of applications far wider. It exhibits the results, matured by some years of study and reflection, of a principle of investigation relating to the intellectual operations, the previous exposition of which was written within a few weeks after its idea had been conceived.
George Boole
There is no Animal in the general singular, separated from man by a single, indivisible limit. We have to envisage the existence of "living creatures,” whose plurality cannot be assembled within the single figure of an animality that is simply opposed to humanity. ... The confusion of all nonhuman living creatures within the general and common category of the animal is not simply a sin against rigorous thinking, vigilance, lucidity, or empirical authority, it is also a crime. Not a crime against animality, precisely, but a crime of the first order against the animals, against animals.
Jacques Derrida