Loop Impact

Force and Impact, Loop Impact

Force and Impact

In mechanics, force produces acceleration in an object. The same concept can be used in system dynamics to describe how any time-varying signal can cause acceleration in a stock – a dynamic variable. That signal may be exogenous or come from another stock. In the Newtonian Interpretive Framework, the effect […]

Loop Impact

Balancing Loops: Growth and Decline

Early on in a system dynamics (SD) course, it is usual for a learner to be introduced to two types of first-order balancing loops: one where the stock grows, and one where the stock declines. Death Process Take the decline situation first. If there are no births or migration, a […]

Force and Impact, Loop Impact

Reinforcing Loops and Growth

I have often seen the following causal loop used in system dynamics presentations to explain a reinforcing loop: Figure 1: Causal Loop Diagram of Simple Birth Process The argument then runs: the more population, the more births, hence more in the population; thus,“ the population grows. Fortunately, I never hear […]