Abstract:

In the development of QFD (Quality Function Deployment) system, it is found that there is a conflict between external conceptual ambiguity and internal exactness in computer, or between qualitative expression and quantitative handling. The “linguistic variable” is considered as one of the most effective means for dealing with these fuzzy problems. In this paper, the definition and realization of two kinds of linguistic variables are presented with their strong and weak points compared. One is Zadeh′s linguistic variable, which is defined by L. A. Zadeh in 1974. The other is similaribility linguistic variable, which is defined by the authors to express the similar degree between ideal and current meanings of the linguistic word if the variable is changed.

Key words: quality function deployment, voice of the customer, voice of the engineer, linguistic variable, fuzzy process