The Methodology of Quality Function Deployment with Crisp and Fuzzy Approaches and an Application in the Turkish Shampoo Industry

Abstract. This paper employs Quality Function Deployment (QFD) methodology to translate customer needs and requirements into the quality characteristics to improve quality for an existing product to develop a new consumer product. The traditional quality function deployment technique consists of six steps. The purpose of the first step is to measure the voice of the customer that reveals his/her needs and wants using a questionnaire form and a face-to-face interview with sufficient number of customers to do an appropriate observation. The questionnaire is applied to both the observed firm and other competitor firms so as to figure out, through customers ’ competitive evaluation, the rate of importance of the customers’ complaints. After determining necessary technical requirements by experts and employers with the brainstorming and other quality control tools, the fourth step provides the relationship between technical characteristics and customer needs. The following step points out the technical assessments. At the last step, quality planning is designed. The study consists of two approaches to develop a new shampoo using quality function deployment technique. The first one is the crisp approach. In this approach, traditional QFD technique was employed to build a quality plan for a new shampoo. In the second stage of this study, fuzzy approach was used. This approach centered on the application of possibility theory and fuzzy arithmetic has been developed to address the ambiguity. At the final stage of the study, these two approaches have been compared with each other