Propagation of parameter uncertainties to system dependability

Uncertainties introduced during data collection, modeling, and design of a wastewater treatment system can significantly affect the process performance, cost, reliability, and maintainability of the system. A simple design model of a wastewater treatment system was studied for the case of uncertain technological coefficients and optimized with respect to the design variables to illustrate the application of dependability criterion to the system design. The transmission of uncertainties from technological parameters to process variables, cost of increased dependability, and the conditions at which dependability is limited by design constraints are studied by a sensitivity analysis with a factorial design approach. Analysis of propagation of parameter uncertainties could be a useful design tool for choosing overdesign factors. A sensitivity analysis of the process performance in relation to design variables provides quantitative information for choosing the most desirable settings of the design variables.