What Do We Mean by “Systems”?

“What do you mean by ‘systems’?” This is the most common question I get when I tell someone I’m teaching a systems class. “System” is a concept so universally applicable that its meaning relies almost entirely on context; my interlocutor may be thinking something along the lines of, “I wonder if he means ‘computer systems’?” So I need to clarify. The class is about general systems theory; how all systems work — a broad subject indeed! (In our class we do focus a bit; we’re concerned with systems through the lens of interaction design.)

So what do we mean by ‘systems’ in this context? At its most basic, when we talk about a system we mean a collection of parts that relate to one another in particular ways so that the whole can serve a purpose. All systems — an automobile, a cat, a business — can be boiled down to this statement. As Donella Meadows pointed out, this means systems must have three kinds of things:

  • its constituent elements,
  • the interconnections between them, and
  • the function or purpose they serve when working together.

While it’s useful to break it down in this way, we need to keep reminding ourselves this is a holistic subject; we are less concerned with the constituent parts of systems than with the behavior they exhibit when they work together. (Russell Ackoff: “the performance of the whole is never the sum of the performance of the parts taken separately, but it’s the product of their interactions.”) We can’t study the whole without understanding its parts. That said, we need to constantly re-focus our perspective to take in the bigger picture if we are to stay true to the nature of the subject. This zooming in and out, while making abstract subjects understandable and engaging, are the primary challenges of teaching this subject.