The Government Accountability Office (GAO) has urged the Department of Defense (DOD) to enhance its implementation of a Modular Open Systems Approach (MOSA) in weapon system development. MOSA is designed to simplify upgrades and reduce long-term costs by using modular, plug-and-play components. A review of 20 DOD programs revealed that 14 had applied MOSA to some extent, but none conducted a formal cost-benefit analysis to evaluate its long-term value.
Programs often focused on short-term cost and schedule priorities, which contributed to a lack of attention to MOSA’s potential for long-term savings, faster upgrades, and greater flexibility. The report stated that without formal cost analyses, decision-makers are overlooking the lifecycle benefits that modular designs could provide.
Several challenges have reportedly prevented widespread adoption of MOSA. Many programs failed to integrate key planning steps for modularity into early development, leaving them ill-equipped to include MOSA in critical investment decisions. In addition, military services have not assessed their resource needs or allocated sufficient expertise to support MOSA effectively. Existing DOD policies contain gaps, particularly for acquisition programs with accelerated timelines, such as those designed for rapid prototyping or fielding within five years.
Coordination issues across weapon programs further limit MOSA’s potential. Without collaboration, opportunities to share common components and reduce costs are often missed, resulting in inefficiencies and delayed progress. Programs that do not prioritize interoperability may also struggle to adapt quickly to emerging threats or integrate new technologies.
The GAO issued 14 recommendations to address these challenges. These include requiring formal cost-benefit analyses for MOSA, improving planning and oversight processes, and closing policy gaps. While the DOD has made some updates to acquisition and engineering policies, the GAO emphasized that further action is necessary to ensure consistent and effective use of MOSA across all programs.