When used in conjunction with such concepts as modularity and functional partitioning—the use of self-contained functional components to build systems—the open systems approach was also expected to reduce costs, make technology upgrades easier, and lessen the reliance on military-unique systems. The goal was to promote “plug-and play” (or, at the level of operating forces, “plug-and-fight”): different products, including technology upgrades and modular technological add-ons, that could be swapped in and out of the larger system with no delay and no degradation of performance.
That was from Ronald Fox’s “Defense Acquisition Reform” book discussing the DoD’s approach to modular architecture back in the 1990s. Progress on modularity was to be reported regularly through the DoDI 5000.02-R.
20+ years later, we are still having the same discussions on moving the modular open-systems architectures (MOSA). Indeed, the FY 2017 NDAA made a requirement for MOSA. Perhaps more work should be done on investigating previous efforts to understand what structural impediments to modularity exists, and why it failed in the past. In my perspective, the FY 2017 requirement for MOSA is still hopes and dreams.
The only place I see it really taking shape is through the services’ enterprise tool developments through containerization, allows software to run the same on different platforms, and the use of microservices, which are independently deployable components from which different applications can build around.
Acquisition programs are strongly incentivized to prioritize absolute performance on Day 1 and time to IOC over any future considerations. In effect, acquisition has an extremely high discount rate, even though it is allegedly planning over long time horizons. MOSA is an opportunity to pay more and take longer today, in order to pay less and be faster in the future. It’s a very hard sell within the Services.