The limits to resutls structure endeavors to bring a balance between a current state and a desired state though more often than not the action is limited by some constraint. There is also a video
for this model which is component of the Systems Archetypes Course
The structure begins with a basic Goal Seeking structure where [action] is attempting to bring a balance between the [desired state] and the [current state].
Typically action requires resources of one type or another and it's this resource constraint that typically catches people off guard. And sometimes the resource constraints just have to be accommodated. Nine women can't have a baby in one month.
The simulation structure is equivalent to the causal loop where [gap] = [desired state] - [current state]. The definition of [action] is a bit more complex. [action] = IfThenElse([gap] >= [constraint], [constraint], [gap])
If we simulate this structure in a generic form with [desired state] = 1, [current state] = 0, and [constraint] = 0.3 we find that the [desired state] is reached after a few times steps. The sharp transitions in the graph are due to the Simulation Time Step = 1.
Please spend some time running the simulation with different initial values to get a sense of the behavior of the Limits to Results structure. Also change the values for the Simulation Time Step in Settings to 0.5, 0.25, and 0.125 to see what effect that has. Can you explain why?