The Australian Stocks and Flows Framework (ASFF) was developed to assess the biophysical longevity of the Australian economy, with top-down coverage of the whole physical economy based on bottom-up process-based detail. The ASFF employs mass-balance identities associated with stock and flow dynamics throughout the national economy and associated interaction with the environment. We show that the ASFF shares common features with complementary approaches, including Mass Flow Analysis, Physical Input-Output Tables, and Life Cycle Analysis, but is distinctly different from these because the biophysical processes throughout the economy and environment are represented explicitly. The detailed physical processes modelled have a strong empirical basis, being calibrated with six or more decades of historical data. Given the coverage of the entire economy in physical terms, it provides for many subject specific analyses such as water, energy, climate change, etc, which can also be assessed in integrated analysis of scenarios to 2100 in order to highlight conflicts, trade-offs, and synergies. The ASFF can be applied and adapted to represent specific interests in more detail and context, as demonstrated by multiple applications of the ASFF. Overall, it is designed to explore the possible trajectories of the national economic system over the long term within irrefutable biophysical constraints, and thereby inform development of appropriate policy. The open biophysical nature of the ASFF is intended forexploration and learning, rather than being normative or policy prescriptive.