Developing and assessing commonality metrics for product families

Abstract

To be competitive in today’s global economy, firms must deliver more products that are viable in the marketplace for shorter times. The use of product families allows firms to meet these needs in a cost-competitive manner. The determination of which components to share and which should be unique is very important to the development of product families.Commonality metrics are presented with the goal of assessing (at the early stages of development) the ability of the product family to reduce costs. The methodology of process-based cost modeling is applied to project product development, fabrication, and assembly costs in both the standalone and shared situations. A case study of two automotive instrument panel beams is analyzed. Linear regression analysis shows that when compared to total cost savings, a simple piece commonality metric and a fabrication investment-weighted metric have higher R2’s than a mass or piece cost-weighted metric. When correlated to fixed cost savings, the fabrication investment-weighted metric has the highest R2 (0.62) and is significant at the 0.025 level. Fixed cost savings are proposed as the desired quantity for assessing product family efficiency.