(TRL/MRL 3-4), existing designs or experimental data can be used for more realistic design and simulation of the system. When more designs and data become available with prototype implementation (TRL/MRL 5-7), engineering heuristics (e.g., the choice of separation technology, typical reactor aspect ratios 66 ) and empirical models can be used to establish more mathematical connections between QSD inputs and the system inventory. For technologies with higher TRL/MRL (7+), these connections may be able to be mathematically represented based on first principles using mechanistic models in design and process algorithms. As examples, electricity consumption of a pump can be calculated using fluid flowrate, total dynamic head, and pump efficiency, and biomass growth can be modeled using metabolic reactions and fluxes. Notably, regardless of the level of complexity of the selected algorithms, uncertainty of the algorithm inputs and parameters should be considered; this uncertainty could be particularly important for earlystage technologies where the algorithms often rely on estimations, theoretical values, or very limited experimental data.