To be able to perform life cycle assessments (or any other type of environmental assessment) of a specific good or service, one needs to have inventory data for the complete supply chains. Due to the amount of data needed in order to be able to perform an LCA study of a full supply chain it is practically impossible to collect and organize data of the complete background system without having access to a background LCI database. The ecoinvent database is a background database; you can use your time to collect data for your specific foreground system, while using ecoinvent for the background.
The ecoinvent database is currently the most widely used LCI database which offers fully interlinked unit process supply chains for all products present in the database. Datasets cover all relevant environmental flows, such as resource extractions, land use and emissions, as well as all material and energy inputs and products of an activity. By offering data on the unit process level, the ecoinvent database ensures transparency over the whole supply chain. The ecoinvent database version 3 increases transparency by allowing data providers to use mathematical relations. Thus, the users can see not just the amount of certain exchange, but also the underlying function of how it was calculated.