Concept
Cynefin framework
Also: Cynefin
A sense-making framework by Dave Snowden that helps decide how to act by first asking what kind of system you are in: clear, complicated, complex, chaotic or confused.
Cynefin (Welsh, roughly the place of your many belongings) was developed by Dave Snowden from around 2000, starting at IBM. It does not sort problems into boxes; it asks which domain a situation is in right now, because each domain calls for a different way of acting.
The framework distinguishes ordered systems (clear and complicated), the complex domain, the chaotic domain and, in the middle, confusion (aporia) — the state of not knowing which of the others applies. The current version is often called the five-domain or "5C" variant.
The central idea: fit the method to the context, not the context to the method.
Further reading: cynefin.io/wiki/Cynefin