Causal loop diagrams enable groups to visualize the systemic structures underpinning the patterns of actions and events we observe. Creating causal loop diagrams helps to identify leverage points where interventions in a complex system will be more effective and efficient.
When to use it?
Frame: Causal loop diagrams help you to frame the system. Use it early in framing to make sense of complex or counter-intuitive system dynamics.
How to do it?
Write key variables and show influences with arrows. The variables can be thought of as “stocks” that can go up or down, like the amount of water in a bathtub.
Label the influences as proportional or inverse. Proportional influences mean that more/less of A leads to more/less of B. Inverse influences mean that more/less of A leads to less/more of B.
Mark the time delays with parallel lines. Time delays are important to recognize because of the effect they have on trying to steer or control the system.
Count the number of inverse relationships in each loop.
Draw either a balance (even) or snowball (odd) icon in the loop. Balancing loops are goal-seeking and will resist perturbation. Reinforcing loops snowball in their growth or collapse and are sensitive to perturbation.
Due to its technical nature, this activity works best with 1-5 people.
About an hour.
Pros and Cons
- Provides insight into the systemic structures that perpetuate current patterns.
- Shows not just how the system works, but where to intervene to transform the system’s dynamics.
- Causal loop diagrams are not intuitive. They work best with audiences with a working knowledge of systems thinking, or else require some education before use.
- Causal loop diagrams are dynamic, but not adaptive. They do not show how systems adapt and evolve over time.
- Due to the technical nature of causal loop diagrams, facilitators should only use this method if they have personal experience in creating these diagrams.
- Sometimes the influences are called positive and negative, rather than proportional and inverse. Feedback loops are also sometimes referred to as positive and negative, rather than reinforcing and balancing. We recommend avoiding that terminology because it confuses participants. Negative feedback has a common definition that is different from the specialized meaning in causal loop diagrams.
- Encourage groups to not just map the system, but to explore the implications. Where are the leverage points? How would you change the structure of the feedback loops to create a more desirable pattern?