A novel method for evaluating population accommodation level of adjustable products based on interval estimation

Abstract

In designing adjustable products, their proper adjustable ranges need to be determined based on an accurate accommodation level evaluation method. Previous accommodation level evaluation methods have employed point estimation for representing an adjustable product's population accommodation level. However, a point estimate of population accommodation level is limited in that it lacks 1) information regarding the precision of an estimated accommodation level, and 2) the capability to conduct statistical comparisons of the differences between accommodation levels of multiple designs/products. Therefore, as a remedy for such limitations, this study developed a novel population accommodation level evaluation method that incorporates both point and interval estimation. The method evaluates an adjustable product's accommodation level on the basis of the adjustable range provided by the product and a set of fitting product configurations of multiple individuals. The method consists of three parts: 1) an accommodation level is evaluated for each individual for a given adjustable range, 2) a population accommodation level is determined based on the obtained individual accommodation levels, and 3) a confidence interval of the population accommodation level is generated. The descriptions of the developed method are provided, presented along with its advantages. Then, a case study is conducted to demonstrate how the method can be applied to practical design problems. Lastly, the practical implications of the developed method are discussed along with some possible future research directions.