Decision variables may include system configurations, detailed design decisions for individual unit operations, operating conditions, and end-of-life options. For established technologies, values and distributions of the decision variables are typically derived from literature and/or industry. For example, while RO systems can operate across a broad range of contaminant rejection levels, analyses of RO for micropollutant treatment (e.g., endocrine disrupting compounds, antibiotics, pharmaceuticals) will likely evaluate higher and narrower ranges of rejection than those evaluated in seawater treatment. However, for early-stage technologies with lower technology/manufacturing readiness levels (TRLs/MRLs), values of the decision variables may be highly uncertain as designers and/or operators characterize the landscape of technical feasibility, thereby necessitating the evaluation of wide ranges for decision variables and robust consideration of uncertainty in QSD execution (Section 5.2).