Thinking in systems – a primer

So, what is a system? A system is a set of things—people, cells, molecules,
or whatever—interconnected in such a way that they produce their own
pattern of behavior over time. The system may be buffeted, constricted,
triggered, or driven by outside forces. But the system’s response to these
forces is characteristic of itself, and that response is seldom simple in the
real world.
When it comes to Slinkies, this idea is easy enough to understand. When
it comes to individuals, companies, cities, or economies, it can be heretical.
The system, to a large extent, causes its own behavior! An outside event
may unleash that behavior, but the same outside event applied to a different
system is likely to produce a different result.