Sensitivity Analysis of the Advanced Missions Cost Model

Strategic decisions with regard to system architecture, technology investment, and mission planning for complex projects must balance cost, risk, and performance – potentially across years of development and operation. Cost models are used to translate program and system elements into financial considerations. Oftentimes, different mission options will be analyzed to determine their costs relative to each other and inform development decisions. Cost estimates often forecast years into the future, and parameters are usually uncertain. As such, it is important to perform sensitivity analyses and examine how the results behave in response to changes in the underlying assumptions. Cost sensitivity to particular parameters can be used to illustrate programmatic risks – for example, by revealing that a small variation in a particular parameter can result in massive cost increases. Similarly, these analyses can illuminate areas where development of capabilities outside the specific system being developed can result in cost savings. This paper presents a sensitivity analysis of case studies comparing the cost of open- and closed-loop life support systems for a space station, moon base, Mars transit habitat, and Mars base building upon previous work by Jones using the Advanced Missions Cost Model. The response of the cost estimated for each of these different cases are examined, focusing on the impact of variation of difficulty, a subjective model input. The implications of the results are discussed along with general observations on the use of sensitivity analysis in life cycle cost analysis.