An interrelationship digraph (aka network diagram) helps you see relations and influences between several concepts – even if those concepts are very different. You can also use it to identify critical issues and key drivers of a problem.
You do this by drawing an arrow indicating if one concept influences another.
The concepts with only arrows going out is considered a driver.
The concepts with only arrows coming is is considered an outcome.
An interrelationship digraph is considered a 7M tool.