The Pentagon Must Activate This Powerful, Underused Approach to Acquisition

MOSA Summit 2023 (Photo Credit: U.S. Army)

HII’s Missions Technologies division president Andy Green recently penned an op-ed that highlighted Modular Open Systems Approach (MOSA) as a game-changer for Pentagon acquisitions. This op-ed explains how open architecture—already required by law—can accelerate delivery, cut costs, and boost interoperability. Check out the op-ed in Defense One below.

The Pentagon must activate this powerful, underused approach to acquisition

The modular open systems approach is already encouraged. It’s just not used enough.

(November 6, 2025 by Andy Green) As Secretary Pete Hegseth pushes to speed up the development and fielding of new weapons and systems, he should look to a powerful, yet underused tool: modular open systems approach. The law already requires MOSA to be used in major warfighting programs “to the maximum extent practicable” and Secretary Hegseth’s own Systems Engineering and Architecture office has been pushing the approach since February. It is direction that, if enforced, could do more to speed acquisitions and cut costs than any process reform under consideration. So why hasn't it worked? Because warfighting acquisition, in practice, continues to prioritize closed, proprietary architectures. Program offices lack the expertise and incentives to enforce open standards. Industry resists sharing interface specifications that might invite competition. And without senior leaders demanding MOSA compliance, vendor-locked systems that take decades to upgrade, with every modification requiring costly negotiations with a single contractor continue to be delivered. The inability to deliver needed capability on time and at cost helped spawn today's wave of venture-backed defense startups. These companies offer real promise—but if they also build closed product ecosystems, they simply replace one proprietary problem with another. What the Pentagon needs is compliance with an existing framework—MOSA—that enables established primes and new entrants to compete and collaborate. Why MOSA works better… Read Green’s full perspective in Defense One here.