A system is a recognizable, differentiated complex of other things, that exists over time, and is thought to have identity beyond the sum of its parts.  As such, it is a complex type of relationship.  Certain key types of systems that we're concerned about in business include applications, networks, and organizations.  Organization is one of our topmost categories as well, so that it is an example of the same concept appearing at more than “level” in the ontology.  This is a demonstration of the inability of information to obey the law of gravity (there is no absolute “top” in this universe).

Figure 22

Systems are assembled from resources of all kinds.  They are differentiated things, and thus have identifiers.  A system spans locations, both logical and physical.