Design for Extremes
• Design for extremes implies that a specific design feature is a
limiting factor in determining either the maximum or minimum
value of a population variable that will be accommodated.
• For example, clearances, such as a doorway or an entry
opening into a storage tank, should be designed for the
maximum individual that is, a 95th percentile male stature or
shoulder width.
• On the other hand, added space in military aircraft or
submarines is expensive, and these areas are therefore
designed to accommodate only a certain (smaller) range of
individuals.
• Reaches, for such things as a brake pedal, is designed for the
minimum individual, that is, a 5th percentile female leg or arm
length. Then 95 percent of all females and practically all males
will have a longer reach and will be able to activate the pedal or
control.