A Modular Open Systems Approach (MOSA) is becoming critical in Department of Defense (DoD) systems. If you're unfamiliar with this critical system design approach (or need a little brush-up) you're in the right place (and should totally keep on reading to discover the 5 core principles).
But first, a few quick basics. MOSA is a business and technical strategy for easily developing new defense systems or modernizing existing ones. This will help the Department of Defense provide joint combat capabilities required for 21st century warfare.
MOSA also provides the ability to support and evolve these 21st century capabilities over their total life-cycle.