Even though functional characteristics and various forms can be measured directly and objectively, many designers and engineers still fail to clearly evaluate product criteria due to consumers’ subjective inputs, which change over time. To appropriately evaluate product criteria, an effective design decision making analysis is required. In this study, we propose a methodology to assure this harmony using a mobile phone product family design scenario. Customer perceived utility of design features are first gathered using a questionnaire (with more than 500 responses), and then modeled using multi-attribute utility theory (MAUT) to allow for clustering based on consumer demographics (e.g., race, gender, and age). Based on the clustering, several mobile phone models are tested for their fitness. The goal of the methodology is to determine the appropriate product family size in order to satisfy customer needs as well as reduce supply chain complexity.