DoD MOSA is an integrated business and technical strategy to achieve competitive and affordable acquisition and sustainment of a new or legacy system or component over the system life cycle. This approach allows the Department to acquire warfighting capabilities, including systems, subsystems, software components, and services, with more flexibility and competition.

Title 10 USC 2446a – 2446c established the mandate for Modular Open Systems Approach to be implemented to the maximum extent possible. The Combat Capabilities Development Center (DEVCOM) Armaments Center (AC) is executing this mandate through the development of the Assured Armaments Reference Architecture (AARA) to govern internal and external interfaces for integrated Armaments Systems. Knowledge of external system integration is critical to the future development of Armament Systems – ensuring lethal capabilities perform as expected on a platform reliably and safely while being sustainable. AARA will serve as the foundation for scoping a developmental effort at the Armaments Center. The architecture provides the framework for each specific type of armament system. The architecture is built to be malleable and tailorable to meet the needs of each specific program as they bolt on additions that are program specific, yet retain the philosophy, approach, and intent behind what it means to be AARA compliant.