A complex system of systems composed of subsystems and services that are part of a continuously evolving, complex community of people, devices, information and services interconnected by a network that enhances information sharing and collaboration. Subsystems and services may or may not be developed or owned by the same entity, and, in general, will not be continually present during the full life cycle of the system of systems. Examples of this architecture include service-oriented architectures and cloud computing architectures.
(NIST SP 800-37 Rev. 1)