Don´t sweat the small stuff - a sensitivity analysis of cost estimate input parameters

When estimating the cost of a large system development project, many assumptions have to be made. Early in a project´s development, many of these assumptions will have large uncertainties. This paper examines the effect on the final results of varying many of the input assumptions. Parametric estimating techniques used in probabilistic estimates are the primary focus, but some assumptions apply to other estimate types. It is expected that some assumptions, such as correlation and input distribution shape, will have a negligible effect on the results while others, such as mass uncertainty and inflation assumptions, will have a more significant effect. The results of this study will allow analysts to focus their efforts on areas that are more likely to impact the results and minimize the effort spent on areas with less impact.