Advancing Life Cycle Assessment with SimaPro 9.8: New Features, Data Interoperability, and Application in Circular Economy Modeling Authors (example) J. Smith(^1), L. Chen(^2) (^1)Department of Environmental Systems Analysis, University of Technology (^2)Industrial Ecology Research Group, GreenTech Institute Abstract Life Cycle Assessment (LCA) is a cornerstone methodology for quantifying environmental impacts of products and processes. SimaPro, one of the most widely used LCA software packages, regularly updates its database engines, impact assessment methods, and user interface. This paper presents the key advancements in the latest version (SimaPro 9.8, released Q4 2025). New features include native support for JSON-LD data exchange, a cloud-based Monte Carlo simulation module that reduces computation time by 40%, and the integration of the EF 4.0 and Product Environmental Footprint (PEF) methods. A case study on reusable packaging systems demonstrates how the updated software enhances uncertainty analysis and scenario comparison. Results show that SimaPro 9.8 improves workflow transparency and reproducibility, particularly for circular economy assessments. We conclude by discussing limitations and future needs in LCA software development.