Inventory Resolution and the Interpretive Scope of Life Cycle Assessment – Environmental and Resource Profiles of Passenger Cars

Doctoral thesis, 2026

This thesis investigates how supplier-reported material data can be leveraged to improve the modelling and interpretation of life cycle assessments in the automotive industry. The empirical focus is on vehicle gliders, the vehicle excluding the powertrain, assessed using foreground inventories constructed from the International Material Data System (IMDS) at the level of individual basic substances.
Four appended papers build a progressive argument. Paper I establishes an IMDS-based inventory construction approach using a combustion engine as a test case and shows that inventory simplification affects impact categories differently, with resource-related categories being particularly sensitive to reduced material detail. Paper II extends the approach to vehicle gliders and reveals a portfolio of 55 metals and metalloids, many present in trace quantities yet dominant in the scarcity profile. Paper III tracks the production-phase environmental profiles of four gliders across a 12-year period under a static background model, showing that ozone depletion responds to targeted substitution, climate change scales with platform size and the carbon intensity of material choices, and resource scarcity remains near-stable at the vehicle level while redistributing across subsystems. Paper IV compares high-resolution inventories with a legacy proxy dataset, separates foreground and life-cycle scarcity perspectives, and maps the structural dispersion of scarcity-relevant elements within the product architecture.
The overarching conclusion is that foreground inventory resolution defines the interpretive scope of environmental and resource-scarcity assessment for automotive gliders, not merely its numerical precision. What an assessment can credibly address depends on what the inventory can resolve, and access to detailed, regularly updated, supplier-reported material data is what makes such resolution attainable in practice.