A Structured Methodology for New Product Development Combining QFD and MCDM: Case Study on Router Bits

An integrated approach to product development methods is necessary to connect and rationalize in a single framework the different design phases. Moreover, it allows to map and facilitate the decision-making process, especially when many stakeholders are involved. This paper presents a methodology for the design and development of a new product or component that integrates Quality Function Deployment (QFD) and Multi Criteria Decision Making (MCDM) methods, from the definition of the user requirements to the generation and simulation of the concept models. The evaluation of the results is carried out at different stages of the process with a customer-driven approach. Initially QFD, combined with the Analytic Hierarchic Process (AHP), is applied to define the product requirements from the customer needs. Thereby, the focus of the subsequent development is identified. The concept generation phase is therefore implemented throughout a series of brainstorming sessions. A first selection among the generated solutions is conducted using a summarizing function, according to the level of requirement satisfaction. Several refinements of the chosen concepts are then derived from manufacturability considerations and Finite Element Analyses. Finally, according to the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) a ranking of the developed products is obtained following the performance specifications. The presented methodology was applied to the development of a new router bit with insert knives, allowing to report the decision-making reasoning and to consider the user needs throughout the product design.