1. Method for controlling a hybrid powertrain system, comprising: employing, in a controller, a system constraints function to identify a feasible solution for an objective variable that satisfies a plurality of independent and dependent constraints for an objective function, the objective variable associated with a parameter of the hybrid powertrain system; and upon determining that the system constraints function fails to provide a feasible solution for the objective variable that satisfies all of the independent and dependent constraints, executing a problem recomposition scheme to remove all of the dependent constraints and then reapply and adjust selected ones of the dependent constraints to obtain a feasible solution for the system constraints function that achieves a preferred state for the objective variable; wherein the preferred state for the objective variable comprises one of a minimum and a maximum state for the objective variable; and wherein the system constraints function comprises a plurality of simultaneously solved governing equations defining relationships between variables that are mapped to parameters associated with operating the hybrid powertrain system.