Uncertainty and Sensitivity Analysis of a simplified ORWARE model for Jakarta

Abstract: ORWARE is a system analysis tool for waste management systems based on Life Cycle Assessment. However, it is based on point estimation and does not consider uncertainties involved in the model. As an example application of uncertainty analysis, ORWARE for Jakarta, which models the waste management systems in Jakarta, Indonesia, was chosen for an uncertainty and sensitivity analysis. First the ORWARE model for Jakarta and the most widely used mathematic uncertainty simulation method --- Monte Carlo were systematically described. And the model was simplified and transferred from Matlab to Microsoft Excel to facilitate the further uncertainty simulation. The subsequent procedures consist of selection of essential input parameters, assignment of probability distributions of input parameters, running Monte Carlo simulation and sensitivity analysis with the help of Crystal Ball tool, as well as results summary and interpretation. With the application of uncertainty analysis, the LCA results were transformed from concrete values into probability distributions around mean values and were expressed as confidenceintervals. The probability distributions for LCA results will provide more reliable information fordecision makers as it considers the error and variations in the model. In the end the conclusion from the analysis of the results, the limitation of the current study and the suggestions for further studies are summarized.