Life cycle thinking

Inventory analysis

The inventory analysis step of an LCA includes data collection and calculation procedures to quantify relevant inputs and outputs of a product system. This analysis results in a life cycle inventory (LCI). According to ISO 14040, inventory analysis is an iterative process which sometimes results in the goal and scope definition having to be adjusted for consistency.

Within inventory analysis, product systems are deconstructed into distinct unit processes. Unit process data are the smallest operational elements in the LCI that require input and output data. Unit processes for pharmaceuticals could be for instance: API synthesis, crystallisation, separation, packaging and distribution. To facilitate this analysis, the system is typically partitioned into a foreground system, necessitating specific data collection, and background processes, which can draw upon general data derived from LCI databases (Bruijn et al., 2002). The ecoinvent database is an example of a life cycle inventory database that spans a wide range of sectors. 

For a streamlined inventory analysis and transparent reporting, an overview of unit process data eligible for inclusion in the LCI of a pharmaceutical product is provided in the image below (Van Wilder et al., 2024). It serves as a checklist for inventory analysis and can be complemented with data approximation methods when insufficient data are available.