Addressing data quality in the selection of generic data to link the background system to the foreground system

Context: As global industries decarbonise, new materials and technologies are emerging to support this transition. Life cycle assessments (LCA) can be broken into two systems: the foreground system, for which primary inventory data is collected, and the background system which encompasses the wider economy. The LCA modelling process is iterative and often requires multiple rounds of life cycle inventory (LCI) data collection and modelling. This includes the selection of generic background process to represent foreground materials.

The challenge: Generic LCI databases play a crucial role in LCA and the development of environmental product declarations (EPDs). However, choosing appropriate background data to represent novel foreground processes and materials, such as bio-based materials or new recycling processes, will likely become even more challenging. The new European standard, EN 15941, helps to support the choice of generic data for the production of construction EPDs. For example, it provides rules for reporting the data quality of the relevant generic data used in product LCAs.

Practical approach: In this work, we provide a new technique/framework for tracking the data quality of the specific selection of generic data during the LCA modelling process. This allows LCA modellers to manage the data quality of their background generic data selections and use the visual outputs to discuss with manufacturers and other stakeholders. This transparency and open discussion about data quality and associated uncertainties in the modelling should aid discussions around the sensitivity and variability of early-stage LCA, where poor data could greatly affect the results. The new approach promotes targeted data quality monitoring at the crucial boundary between the background and foreground processes.

Conclusions: We hope that integrating this background-to-foreground generic data quality monitoring into the early discussion for product LCAs will encourage manufacturers and stakeholders to investigate their wider supply chains leading to wider impacts beyond their own practices.