Establishing Relationships Between Manufacturing Sustainability and Performance

The current LCA methods assess a product’s sustainability over its full life cycle, cradle-to-grave. While the number(s) obtained detail the contributions a process makes to a product in terms of energy intensity or the generation of wastes, it is insufficient to optimize a process for both sustainability and performance objectives. The Economic Input/Output Life Cycle Analysis (EIO-LCA) was used to investigate whether metrics could be identified which address sustainability — performance issues in materials processing. This method lends itself to the assessment of processes on a unit time basis while allowing for calculation of resources used and byproducts expelled. Productivity of manufacturing processes is also based on time. For example, material removal rate is related to processing feed, speed, and the geometry and tolerances established during design. A scaled waterjet cutting process was tested to investigate the unit time relationships. The EIO-LCA was conducted and the subsequent environmental impact in the form of total energy consumed and equivalent CO₂ expelled evaluated per unit time, establishing the relationship to cutting speed. Although this is a static LCA at set conditions, it suggests that relationships can be explored between the regulation of resources, productivity, cost and environmental impact by varying the processing parameters.