Systems theory, also referred to as systems thinking, is the study of dynamic systems, which comprise a number of small subsystems that are interconnected and interdependent on each other. Rather than focusing on individual parts, the theory focuses on the links and interactions between the individual parts and their role in making the system function properly. The underlying concept of systems theory is the belief that knowledge can only be derived from understanding the whole rather than the individual parts, which was first stated by Aristotle. It stresses the need for shifting the attention from the part to the whole. Peter Senge said in The Fifth Discipline