Understanding product family for mass customization by developing commonality indices

While the rationale of developing the product family as a means to achieve economy of scale and standardization of production has been well recognized in both industry and academia, the fundamental concern regarding developing the product family lies in the fact that a company must optimize the internal complexity and external variety. With this view, this paper recognizes the necessity to understand the product family through developing commonality measurements. The goal of the paper is to present design and process engineers with insight into product family design and its manufacturability. In this paper, two sources of commonality are identified: the component part commonality and the process commonality. The formulation of the component part commonality is based on the mindset of counting the average applications per component part and takes into account product volume, quantity per operation, and the price/cost of the component part. The process commonality index incorporates such concerns as process flexibility, lot sizing, and scheduling sequencing into one analytical measurement. The effects of these two commonality indices on product family design are examined in response to changes in their parameters. Accordingly, the managerial implications are derived. In order to facilitate the understanding of the product family, the feasibility of evaluating the product family by relating commonality indices to the system's performance is discussed.