Developing a Methodology for Accurate Product Carbon Footprint Calculation in Machining Processes

Given the increasing demand for sustainable production, the product carbon footprint (PCF) is gaining importance as a measure of ecological sustainability. The PCF offers numerous advantages, such as the quantification of greenhouse gas emissions and the identification of emission-intensive processes, but it also presents challenges. The biggest obstacle to its application in production is the complexity and interpretative nature of the various standards and norms, such as PAS 2050, DIN EN ISO 14067, and the Greenhouse Gas Protocol (GHG Protocol), which often lack specific guidelines for production processes. To improve the applicability of such standards and norms in production and to enable the precise capture of sustainability-related factors, more specific guidelines are necessary. This work develops a methodology for the accurate calculation of the PCF for machining processes, considering current standards, norms and existing methodologies. The three aforementioned standards and norms were compared and evaluated in terms of their applicability to machining processes. Subsequently, the key input and output streams of a machining process were identified, and corresponding guidelines were created. The developed methodology and guidelines were validated in a real machining process on a milling machine.