Using Digest to implement the pathway participation method for detecting influential system structure

This article briefly defines and describes the pathway participation metric (PPM), a mathematical calculation that can help to identify the linkages between the structure and behavior of a dynamic system. PPM has been implemented in an experimental piece of software called Digest , which we then present. Digest is not a simulation language, but rather a companion to any commercial system dynamics package, which accepts a text version of a simulation model and performs post formulation analysis of the model. Digest detects and displays which feedback loops are most influential in explaining a selected pattern of behavior in a model. Output from a sample Digest run is presented and described.