Abstract: The Model Editor (106) makes simulation modeling easier and more intuitive by extracting essential information and presenting it to the user, and by providing tools to investigate simulation and model robustness, in an interactive, graphical environment. The Model Editor (106) includes a Newton step manager as an interactive, graphical tool. During simulation of a model, the Newton step manager captures matrix norms. Any indications of Newton limiting are also captured. The matrix norms are plotted as a function of iteration count, and the iterations at which Newton limiting were encountered are identified. Newton step manager can also be run automatically using a functional dependency analysis.