抄録
Consumer products are deployed from market-in stage through growing-up stage to maturated stage by gradually shifting their appealing features from fundamental functions to supplemental value-addition over their life stages. This paper investigates the underlying design patterns in such product deployment and proposes an design assessment method toward superior product definition. Product definition means here the objective establishment for respective modules and their features before executing actual design activities. The method is based on quality function deployment (QFD), cost-and-worth assessment in value engineering, cost estimation methods and the revealed patterns, Its validity and effectiveness are ascertained through the analysis of design changes across three different vacuum cleaners for Japanese market in the last three decades.