I don't think that System Dynamics modelling tools offer the depth of control over the governing equations that Modelica has. In addition, Modelica has a nice s

I don't think that System Dynamics modelling tools offer the depth of control over the governing equations that Modelica has. In addition, Modelica has a nice standard library with many physical components that you can link together to form a system. In short, Modelica is better for simulation well-specified physical systems. System Dynamics is good for simulating the approximate behaviour of larger, often poorly understood systems.