FAA STD- Appendix XV (CM in the NAS Life Cycle)

150.1 CM in the NAS life cycle
It is FAA's policy to develop and implement the techniques of Configuration Management in order to achieve required NAS performance, operational efficiency, reliability , maintainability, and safety. The NAS life cycle is complex in that there is a current system which is to be transformed over time into the desired system. Embedded within the overall NAS is a diverse set of subsystems each executing its assigned portion of the NAS mission and each with its own unique subsystem life cycle. These individual subsystem life cycles must be co-ordinated and managed in order that the NAS life cycle be effectively concluded. From the time to time groups of subsystem life cycles must be synchronized so that the incremental capabilities may be introduced into the operational NAS. As a result, interfaces among subsystems must be controlled not only when allocation of functionality to subsystems is defined, but throughout each of the otherwise unsynchronized life cycles of each subsystem.