The implementation of quality function deployment based on linguistic data

Quality function deployment (QFD) is a customer-driven quality management and product development system for achieving higher customer satisfaction. The QFD process involves various inputs in the form of linguistic data, e.g., human perception, judgment, and evaluation on importance or relationship strength. Such data are usually ambiguous and uncertain. An aim of this paper is to examine the implementation of QFD under a fuzzy environment and to develop corresponding procedures to deal with the fuzzy data. It presented a process model using linguistic variables, fuzzy arithmetic, and defuzzi®cation techniques. Based on an example, this paper further examined the sensitivity of the ranking of technical characteristics to the defuzzi®cation strategy and the degree of fuzziness of fuzzy numbers. Results indicated that selection of the defuzzi®cation strategy and membership function are important. This proposed fuzzy approach allows QFD users to avoid subjective and arbitrary quanti®cation of linguistic data. The paper also presents a scheme to represent and interprete the results.