In this paper, software requirements are analyzed by using quantification theory of type 3 (QT3). On the basis of this quantitative analysis, by utilizing the house of quality (HOQ) matrix of quality function deployment (QFD), and based on the fuzzy analytic hierarchy process (FAHP) improved by fuzzy technique, a method of mapping software requirements going through the process of software design is proposed. Its effectiveness is presented by applying this method to the development process of the CD-R/RW recording device software.