Every person has unique body measurements, unique habits of movement and unique ideas of clothing, e.g., placement and shape of the neckline, waistline and hemline. Therefore, every dress should (ideally) be designed and made for each wearer by a custom dressmaker, who fits the dress to the measurements of the wearer with an appropriate amount of ease. Dresses were made in this way until the end of the 19th century.
However, the Industrial Revolution introduced the mass production of clothing in standard sizes, known as ready-to-wear clothing. Standard sizes were also used earlier in designing uniforms, especially for the armed forces of various countries. These standard sizes are purportedly arrived at by statistical analysis of large numbers of people. Dress sizes are included in the US standard clothing size and the newer European standard EN 13402. Another standard has been produced by the
American Society of Testing and Materials.
The classification of body measurements into standard sizes has been useful for industrializing the manufacture of clothing. However, the present system is not ideal, since a significant percentage of women do not match one of the 20 common sizes.
Moreover, many styles of dress are not made for all the standard sizes (example,
petite sizes). Unfortunately, more sizes and broader manufacture of styles seem unlikely, since they would likely diminish the economies of scale associated with mass production.