LCA capability roadmap—product system model description and revision

Purpose Life cycle assessment (LCA) practitioners face many challenges in their efforts to describe, share, review, and revise their product system models, and to reproduce the models and results of others. Current life cycle inventory modeling techniques have weaknesses in the areas of describing model structure, documenting the use of proxy or non-ideal data, specifying allocation, and including modeler’s observations and assumptions—all affecting how the study is interpreted and limiting the reuse of models. Moreover, LCA software systems manage modeling information in different and sometimes non-compatible ways. Practitioners must also deal with licensing, privacy/confidentiality of data, and other issues around data access which impact how a model can be shared. Methods This letter was prepared by a working group of the North American Life Cycle Assessment Advisory Group to support the UNEP-SETAC Life Cycle Initiative’s Flagship Activity on Data, Methods, and Product Sustainability Information. The aim of the working group is to define a roadmap of the technical advances needed to achieve easier LCA model sharing and improve replicability of LCA results among different users in a way that is independent of the LCA software used to compute the results and does not infringe on any licensing restrictions or confidentiality requirements. This is intended to be a consensus document providing the state of the art in this area, with milestones for research and implementation needed to resolve current issues. Results and Conclusions The roadmap identifies fifteen milestones in three areas: “describing model contents,” “describing model structure,” and “collaborative use of models.” The milestones should support researchers and software developers in advancing practitioners’ abilities to share and review product system models.