Over the years, representatives of other schools of quantitative analysis have at times critisized the System Dynamics methodology. To investigate the basis for such criticism, I take two advanced forms of quantitative analysis as my starting point: optimisation under uncertainty and Bayesian statistics. These methods can be seen as shared ideals for simplified optimisation and estimation techniques. It turns out that for an important class of dynamic problems, System Dynamics can be seen as consistent with the advance methods, and as an economical way to perform advanced policy analysis.