Open systems have no boundaries. All systems are connected. There are no separate individual systems. This is a difficult concept to wrap our heads around.
Boundaries are artificially created by people to help them separate and clearly examine one problem at a time. There is no such thing as one correct boundary of a system. The boundaries we decide to draw around systems are based on the questions we are trying to answer and the problems we are trying to solve. The boundaries we draw can lead to problems if we fail to keep in mind that they are of our own making and were artificially created by us.
Ideally, we would study a problem and choose whatever boundary best helped to meet the system’s needs. But we are creatures of habit. We become comfortable with the boundaries we typically use. To get a more accurate picture, we should create a new boundary for each problem, have an open mind, and judge every situation on its own merits.
— The Systems Thinker: Essential Thinking Skills For Solving Problems, Managing Chaos, and Creating Lasting Solutions in a Complex World by Albert Rutherford