Systems thinking works by applying the concept of a system to a problem. By assuming that any problem is a system, we can assume that it has all the properties of a system.
A system is a construct that describes some aspect of the physical world that has been created or occurs naturally. It describes an aggregation of interacting components arranged in a particular way.
Systems respond to events, and behind each event is a pattern of behaviour. System behaviour is a consequence of its architecture. A system architecture is defined by its parts, and how they are arranged and connected.
Rather than instinctively reacting to events, systems thinking encourages us to observe events, and discover patterns of behaviour caused by the underlying architecture. Once we understand the underlying system architecture we can start to make predictions about future behaviour and decide what can be done.