(1) (architectural structure) A physical or logical layout of the components of a system design and their internal and external connections. (ISO/IEC 2009, 1)
(2) (Data structure) a physical or logical relationship among data elements, designed to support specific data manipulation functions. (ISO/IEC 2009, 1)
(3) (Generalization structure) a connection between a superclass and one of its more specific, immediate subclasses. (IEEE 1320.2-1998)
(4) The static existence of the system; namely its elements and their relationships. (Created for SEBoK)
(1) and (2) ISO/IEC. 2009. Systems and Software Engineering Vocabulary (SEVocab) - ISO/IEC 24765. in International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) [database online]. Geneva, Switzerland, 2009 [cited December 21 2009]. Available from http://pascal.computer.org/sev_display/index.action.
(3) IEEE. 1998. IEEE Standard for Application and Management of the Systems Engineering Process. Washington, DC: Institute of Electrical and Electronics Engineers (IEEE), IEEE 1220-1998.
(4) This definition developed for the SEBoK.