Period of time in the system life cycle during which a product is integrated into its operational environment and tested in this environment to ensure that it performs as required. (Adapted from (ISO/IEC 2009))
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.