A process that combines system elements to form complete or partial system configurations in order to create a product specified in the system requirements. (ISO/IEEE 2008)
ISO/IEEE. 2008. Systems and Software Engineering - Software Life Cycle Processes. Geneva, Switzerland: International Organization for Standards (ISO)/Institute of Electrical & Electronics Engineers (IEEE) Computer Society, ISO/IEEE 12207:2008(E).
For a full discussion of the role and importance of integration in systems engineering see the System Integration article.