1. A system operative to simulate the robustness of a circuit module, comprising: a component operative to convey an expected distribution of global values associated with the module; a component operative to convey an expected distribution of local values associated with the module; and a modeling component operative to model behavior of the module in response to the global values and the local values and to generate an output indicative of the robustness of the circuit module to local variation over a range of global variation.