Back on topic:

Systems theory seems to basically be object-oriented, meaning it sometimes has problems dealing with self-reference. This should not be a problem for most practical applications but for things like ecological dynamics the complexity is not user friendly.

Cybernetics seems to be a function-oriented approach to the same problem class. It deals with feedback loops as first-order citizens, which in complex ecosystems like desktop operating systems means it has less of a conceptual impedance mismatch.

The former is the popular discipline while the latter fell out of favor decades ago. Perhaps it is time to dust it off.