Critical Examination of Functional Decomposition and Morphology as an Engineering Design Teaching Method

Engineering design is a highly complex cognitive process of solving problems by developing new solutions and products. In the past this process was accomplished using intuition and experience, until a realization came that a methodology must be developed in order that novice designers could produce good solutions. One of the methods was developed in Germany by Pahl and Beitz, who attempted to answer the need by introducing the Systematic Design methodology, also known as the Rational Model. At the heart of the rational model lies the Functional Decomposition and Morphology (FD&M) method for the phase of conceptual design. Nowadays, FD&M is the most popular method taught in engineering schools.
The present research investigates the FD&M method in educating engineers through an experiment conducted on students (N=29) in the faculty of aerospace engineering. Participants were both undergraduate and graduate students. The application of the method was studied in analyzing an existing device and for the purpose of new product design. The research was based on analysis of design reports in the form of submitted homework assignments and of a self-reflection questionnaire that was generated for the purpose of the research. The investigation revealed many difficulties and shortcomings of the FD&M method, classified into 10 different problematic aspects that were recognized and demonstrated. The analysis indicated that the method is quite difficult to apply, is non-intuitive and most of the time is a hindrance to innovation. The results also showed that the method is much more complicated than initially perceived by students.