A Technical History of the SEI

Building and Fielding Interoperating Systems
The Challenge: Interoperability in Evolving Defense Systems
Most of the software-reliant systems that traditionally supported operations in the DoD, particularly
in the military theater—including planning, manpower, and logistics—were designed as
stand-alone systems. They had limited capabilities for net-centric warfare, such as the efficient
and secure exchange of information across a networked force of weapons, sensors, and soldiers.
In addition, acquisition practices, system architectures, and engineering solutions were optimized
for stand-alone systems. The Gulf War I (circa 1990) catalyzed a new emphasis on the timely, efficient,
and secure exchange of information across independently developed software-reliant systems,
with interoperation among them—a particularly significant need because of the war’s multiservice
nature. This critical need was not just in the DoD and with its coalition partners, but in civilian
government and industry as well.
Many organizations recognized that a system of systems (SoS) 55 could help them achieve important
business and mission goals more effectively; however, they needed guidance on how to
create systems of systems out of legacy systems and new systems (either fielded or under development)
that were not necessarily designed to work together. The challenge is significant because
organizations must create systems of systems when it is difficult to know which systems will need
to be involved in the future and when knowledge of system behavior is incomplete. It is equally
difficult to predict what data a system holds that will be of value to others. Finally, in a system of
systems, there is often no practical central control over all the systems involved. The challenge is
complex, with technical, operational, governance, management, and acquisition aspects.
A Solution: Multi-Faceted Approach to Support for Interoperation
The SEI started, in the mid-1990s, to seek solutions to the interoperation of independently evolving
systems, focusing on integrating commercial off-the-shelf products. In 2002–2003, the SEI
conducted the System of Systems Interoperability (SOSI) research project. Through this project,
the researchers realized that interoperability must occur not only at the technical level but also at
the program office/governance level. By 2004, the SEI’s focus shifted to finding a general solution
for the interoperability needs of government and industry organizations as they faced unprecedented
issues in migrating to network-centric operations and systems of systems.
The approach to systems of systems was two pronged: defining fundamental principles and concepts
and developing techniques for putting the principles into practice. Among the principles
were these:
1. Independent and continuous evolution of individual systems means that system-of-systems
behavior cannot be completely predicted.
55 Admiral William Owens introduced the concept of a system of systems in a 1996 paper, defining it
as the serendipitous evolution of a system of intelligence sensors, command and control systems,
and precision weapons that enabled enhanced situational awareness, rapid target assessment,
and distributed weapon assignment [Owens 1996]. The term system of systems is now used in a
variety of settings, beyond those in the original definition.
CMU/SEI-2016-SR-027 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY 216
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