Causal Tracing is the ability to quickly find the causes of model behavior. Vensim's analysis tools make this fast and easy to do. The following steps outline the process in its most commonly practiced form:
| 1. | Start with some behavior that needs to be investigated. Select this variable into the Workbench. |
| 2. | Use the Causes Strip graph to show the behavior of the variable and its causes. |
| 3. | Inspect the graphs to see which cause is most likely responsible. If it is ambiguous, lock the graph and choose a candidate. |
| 4. | Select the variable that is most likely responsible for the behavior into the workbench by double clicking on it. |
| 5. | Return to step two and repeat until you have gone in a circle, found a causal strip that is surprising or gotten down to just Constants and Loookups. In the first case you have found a feedback loop, in the second you will need to study the equation to understand the relationships involved and in the last case you will have traced the behavior of interest to a set of parameters. |
In practice, there is a lot more variety in Causal Tracing. The Tree diagram tools can be used to jump over large sections of a model more quickly than the Causes Strip graph. In many cases, you will want to use the Document tool to study the equation of a variable to make sure the equation is correct. All of the different tools and their configurations are discussed in Analysis Tools.
