Human–Systems Integration (HSI) is crucial because it promotes integration from the very beginning of the life cycle of a system, and Virtual human-centered design seriously considers the human element in the design of the complex system. Orchestrating HSI is mostly a matter of educated common sense, which is simply doing things that make sense according to a well-understood purpose shared by an educated community of people. For a system-of-systems ontology, it is typically easy to define an initial structure of structures, as well as allocating functions of functions onto it. However, it is more difficult to find out new emerging structures and functions that should be incrementally added, removed, modified, split, merged among each other, and so on into the ontology. The human respiratory system is a good example of structure-function symbiosis and minimality. Human lung’s function is to provide oxygen from the air to the blood and exhaust carbon dioxide from the blood to the air.