In this project we developed a classification tool of production processes with regards to its sustainability grades. These grades can be obtained by performing a life cycle assessment analysis (LCA) of a normalized product (functional unit) manufactured by different processes or process chains. A comparison of sustainability grades between the different scenarios allows a classification of processes/process chains regarding their sustainability.

This method of classifying production processes is deployed in a web application called “Sustainability Assessment Tool” (SAT). It enables ICNAP partners and Fraunhofer researchers to perform comparisons and classifications of processes using life-cycle assessment. The SAT works in cooperation with standard life-cycle assessment tools (as OpenLCA) through API connection. Databases can be configured in the platform according to the user’s needs. The validation of this method was performed with Fraunhofer ILT’s laser welding use case. Here, two different welding processes were assessed: laser welding blue and IR (using different wavelengths). The energy measurement system at Fraunhofer ILT considers cooling capacity and electrical energy input.

The method of using a normalized product (e.g., 10x0.5x0.5 mm³ of welding seam) as functional unit overcomes the disadvantage of not being able to compare sustainability grades among different processes. This means that the developed method can classify processes that produce exactly the functional unit. Comparing processes producing even slightly different products, is incoherent with this method, assuming different processes achieve different product qualities.

A suggestion for sustainability assessment of production processes is to set measurable quality properties of the product as functional unit instead of the product itself. In the example of welded seam, properties such as tensile strength, impact strength, and critical elongation can enable a comparison of slightly different products regarding their LCA-scores.