Uncertainty Assessment at Conceptual Design: An Evidence Theory Approach
Unal, R¹; Bondi, S¹; Chytka, T^2
1Old Dominion University; ²NASA Langley Research Center

One of the most critical cost drivers in any space transportation system is operational cost. Since space transportation systems are predominately highly complex, one-of-a-kind systems, historical data is often wanton and therefore cost estimators must often rely on expert opinion to quantify operational cost expectations. To achieve a more robust operations cost assessment, incorporating uncertainty in the estimate is paramount. Expert judgment methodologies using probabilistic analysis approaches have been utilized in prior research to quantify uncertainty in critical system parameters as probability distributions so that probabilistic analysis studies can be conducted. This paper presents a combined probabilistic and evidence theory approach to enhance uncertainty assessments for a space transportation conceptual design case study. The results may provide additional information to the decision makers for uncertainty assessments. Benefits and limitations are discussed.