A Technical History of the SEI

AFSC/ESD conducted a source selection to find contractors to develop a model generic command-center
architecture and functional specifications with supporting tools. ESD awarded research-and-development
contracts to Raytheon and Hughes to build, test, and validate a “product
line” approach to systems development [Hughes 1991]. TRW was later added as a third contractor.
Eight line programs used the PRISM model architecture and supporting tools to realize an estimated
56 percent average savings in cost and an average 66 percent savings in time. These eight
systems were early examples of software product lines.
At the time, the SEI was engaged in developing the Feature-Oriented Domain Analysis (FODA)
[Kang 1990] that analyzes a problem domain across multiple similar systems to identify common
and variable features. FODA serves as the basis for a vast number of subsequent feature modeling
approaches and dialects still in use today. At the SEI, FODA later evolved into product line analysis,
which extended the analysis of commonality and variability beyond features to quality attributes.
The SEI investigation into product lines was also made possible by its concurrent focus on
software architecture. SEI contributions in architecture definition, documentation, and evaluation
were an important part of a software product line approach. Serendipitously, SEI staff members
traveled to Sweden to interview staff at CelsiusTech Systems AB, ostensibly to do an architecture
case study; what they found was that CelsiusTech had taken a product line approach that was
achieving significant results in ship systems built for national defense, a domain of interest to the
DoD. Those results included systems completed in days instead of years, order-of-magnitude
productivity gains, and mass customization where 20 software builds were parlayed into a family
of over a thousand specifically tailored systems. The promise of product lines that was documented
in the CelsiusTech case study [Brownsword 1996] led the SEI to pursue an initiative in
software product lines. The SEI recognized that when developing multiple similar products, there
will be some degree to which they are the same, but there will also be some degree to which they
vary. Economic advantage is achieved through a systematic product line approach that effectively
manages this variation. Creating a software product line depends on establishing a software architecture,
or product line architecture, for the entire set of systems.
Broad Use of SEI Approaches to Software Architecture
The influence of SEI work in software architecture on the DoD has been broad and pervasive.
Major defense contractors, such as Boeing and Raytheon, now have architecture evaluation teams
and architecture evaluation as part of their architect certification processes. Also, U.S. Army staff
have reported repeatedly that use of scenario-based architecture evaluation methods reduces risk
in schedule and cost, improves documentation, and results in higher-quality products.
Moreover, in 2009, the U.S. Army mandated that all Project Executive Offices appoint a chief
software architect (CSWA) to be responsible for oversight and management of software development
within each PEO. The memo specified that the CSWA must earn a Software Architecture
Professional Certificate from the SEI (or another certificate-granting organization with software
architecture expertise). The decision was based on an understanding of SEI work in software architecture
and its impact and, in particular, a recent impact study of the use of SEI architecture
evaluation techniques in the Army [SEI 2009]. Also, the SEI conducted a study of the impact of
the Army Strategic Software Improvement Program (ASSIP)-sponsored QAWs and architecture
evaluations using the ATAM. Ten out of 11 programs that responded to the survey indicated that
ATAM/QAW produced better results than they traditionally obtained.
CMU/SEI-2016-SR-027 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY 237
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