 Synthesis of improved courses of action arises from mitigating bad (vicious circles) self-reinforcing feedback loops, exploiting good (virtuous circles) and goal-seeking feedback loops, and iteratively optimizing them, typically using parameter-driven simulations.Leverage point models accomplish this simulation capability in software tools that follow system dynamics conventions.These conventions capture model structure and attach algebraic relationships to all the variables appearing in a diagram, including time span and steps.