What Does Boundary Values Mean?
Boundary values are a set of conditions applied to a mathematical equation. The boundary values represent the extremes of a value set. In ergonomics, upper and lower boundary values are based on the 5th and 95th percentile of a selected population. Boundary values may also be called boundary conditions.
WorkplaceTesting Explains Boundary Values
In the workplace, boundary values are used to provide the outer parameters when creating ergonomic designs. The information used to determine boundary values for a particular design project is obtained from existing databases containing anthropometric information.
The percentiles used to compute boundary values are based on a selected population and may vary by geographic region, gender, or other criteria. For instance, to create a boundary value that addresses 90% of an adult population, the lower boundary would be based on the 5th percentile of female members of the population and the 95th percentile of males. The generally accepted boundary values for ergonomic designs in the workplace are the 5th and 95th percentile.
A design is usually considered to be ergonomic if it is fit for individuals whose physical characteristics fall within these boundary values. Often to meet the needs of the full value range, the specific work area or tool will need to be adjustable. If a design cannot incorporate this flexibility, such as the design of a fixed countertop, it may be based on the average user or the 50th percentile.
In other instances, a design may be made suitable for the maximum number of users by being made suitable for the smallest user; applying the lowest boundary value. Boundary values for different body parts and muscle groups may be used for different workplace settings and tools.