A unit process model based methodology to assist product sustainability assessment during design for manufacturing

As the growth in demand for sustainable manufacturing continues, companies must begin to make conscious decisions with regard to the sustainability of their products. Thus, design and manufacturing engineers must consider economic, environmental, and social aspects simultaneously when developing products and process flows. The purpose of this research is to develop a sustainable assessment methodology to both improve the accuracy of existing approaches in identifying the sustainability impacts of a product and to assist manufacturing decision makers. The methodology developed utilizes unit process modeling and life cycle inventory techniques. Combining these approaches allows for conducting product sustainability assessment at the process level by quantifying a selected set of sustainability metrics. A demonstration of the methodology to assess three design alternatives for a bevel gear is presented. The developed methodology is capable of quantifying the sustainability metrics by aggregating information from the process level. It was found that the various metrics require different aggregation methods from the manufacturing process to the manufacturing system level. The general approach can be applied to aid the investigation of tradeoffs during the design decision making process for a wide range of products.