Systems thinking builds on our understanding of natural and man-made systems. It emphasizes that we need to understand how the whole affects its parts and how the parts affect the whole. This is different from traditional thinking, which assumes that the parts are independent of the whole. It is a set of techniques and an overarching mind-set that “problems” can best be solved by considering the component’s relationship to the overall system and its environment.
This type of thinking is revolutionizing many fields of study. For example, we now know that the pain that you have in your back may be caused by one leg being longer than the other so that the skeletal subsystemis skewed. In other words, close examination of a person’s back will reveal the symptoms (i.e., back pain), but not the causes (i.e., leg length differences). In traditional thinking, diagnosis of back pain focuses exclusively on the pained area of the body.
Systems thinkers tell us that there are two types of systems—closed and open systems. Closed systems function as systems relatively independent of their environment; open systems are constantly exchanging material, energy, and information with their environment. An example of a closed system is the circulatory system of a fish versus mollusks. In fish (and other vertebrates), the blood circulates within vessels of different lengths and wall thicknesses, so its circulatory system is relatively closed to the rest of its body cavities. In mollusks (and most invertebrates), there are no vessels and the blood circulates within the tissues of the entire body cavity. The key notion for our purposes is the fact that system openness is a relative state, not an absolute state.
Sometimes the components or elements of a system function as subsystems within a larger system. A subsystem is a collection of components or elements with a smaller aim within the larger system. Hence, there are various levels of systems that operate interdependently. A prime example here would be the financial subsystem’s impact on and relationship with the larger national economic system.