Focuses on answering the following questions: - What are the root causes (vs symptoms)? - Who influences them? - What am I able to influence? - What could I do differently? - What would be the impact? - Who else will be affected? - How does this make me feel?
This could be via the existing system or by creating new system structure. We look for high leverage interventions (which via feedback make a big difference for a small change). Mapping the expected impact of these interventions helps us to identify the likely consequences of these interventions and the risks. We can also consider the purpose of the system and other ways it could be achieved with the resources in the system.
Vensim 
is a useful software tool for creating and analysing Causal Loop Diagrams. It allows us to understand feedback, trace root causes of problems using driver trees and the consequences of potential interventions using effects trees.