Understanding systems : a grand challenge for 21st century engineering Examples of systems System properties Knowledge discovery Examples of mechanical systems undergoing transitions Biological systems Role of variability in systems Our book presents a unique and original viewpoint on natural and engineered systems. The authors goal is to propose and explain core principles that govern the formation and function of simple and complex systems. Examples are drawn from a broad range of topics from common materials and manufactured structures to the behavior of cells organisms and socio economic organizations. We provide a technical discussion of key engineering principles without the use of mathematics so that we may describe for a general audience how the systems of daily life form operate and evolve. We use analogy and illustrations to show how the components self organize and scale to form complex adaptive systems. In this way we hope to understand how those systems come to be achieve stability and suddenly transition to new equilibrium states including the sudden onset of economic recessions ecosystem collapse the evolution of species development of cancer and other wide ranging topics. The existential role of component variability in these processes is emphasized. This book targets engineering instructors and undergraduate students curious to explore the grand challenges facing society today so they might build productive and long lasting careers in science and technology. The six essays can be used to frame classroom discussions on systems from a broad range of disciplines. The essays are designed to appeal to those with a basic science and engineering background as we illustrate many fundamental engineering concepts in our descriptions of system behavior. We also hope our book appeals to curious members of the general public who are interested in understanding foundational ideas. Publishers website