By standardization is meant the reduction of any one line to fixed types and sizes. Thus in the case of the manufacturer of shoes he selects a few types that, in his opinion, will find favor in the market. But each foot is not measured and a shoe of the required type made to these measurements. A limited number of sizes of each type is manufactured, these sizes being selected, by previous experience, so that any average man can find a pair that will fit him. The same holds true for the case of electric motors discussed above, and in fact for the entire field of manufactured products.

p. 42 - Principles of industrial organization, 1913