A Technical History of the SEI

Ada Adoption Handbook
The Challenge: Where and When to Adopt Use of the Ada Language
When the DoD mandated the use of the Ada language, compilers, runtime systems, and the supporting
programming environments were just coming to market. While they held the promise of
making software development for real-time systems more effective, there was considerable uncertainty
on the part of DoD program managers who had to make difficult decisions about the technical
maturity and the production quality of the language support as applied to their system developments.
In some cases, although compilers and supporting environments were available, code
generators for the embedded processors were still in development and the runtime systems for
those processors unproven. As a result, there remained those who were skeptical that a higher order
language could be used for real-time embedded systems. While there were some early success
stories and considerable pressure on the DoD program managers, there was also a considerable
amount of uncertainty, often based on bias or myth rather than hard data.
A Solution: The Ada Adoption Handbook
The SEI had committed to helping those DoD program managers who chose to use Ada to do so
successfully. Efforts such as the Ada Embedded System Testbed were initiated to provide program
managers with the kind of data that allowed them to assess the maturity of the language support
for specific embedded processors. While the testbed was under development, compiler maturity
for specific processors was just one of many questions that remained unanswered. In some
cases, program managers were avoiding the decision or leaning toward the use of other high-level
languages because of the lack of authoritative data (of any sort) and the lack of “honest broker”
guidance. The Air Force program manager for the SEI asked that the SEI develop definitive guidance
upon which DoD program managers could base an informed decision.
By that time, the SEI had several members of the technical staff with a great deal of experience
with Ada and with real-time systems. Nevertheless, the requested effort was daunting since there
was so much difference in opinion in the software development community between those who
understood the promise of Ada and those who were adamantly opposed to its use. The SEI committed
to providing an honest assessment, providing the pros and cons of adopting the language,
independent of DoD mandate.
The SEI embarked on a strategy that has been employed on many of its efforts. Relying on its internal
expertise to separate fact from fiction, the SEI invited comment from those with experience
with the language, whether positive or negative. The handbook authors organized this information
and supplemented it with their own experience to produce a first draft that was distributed widely
for comment. Comments on this first draft were addressed to produce a second draft, which was
distributed for additional comment. Subsequent drafts followed the same process. Recognizing
that the SEI was dealing with a moving target in that the products to support Ada were maturing
at an accelerating rate, the SEI and the Air Force agreed that it was in everyone’s best interest to
distribute the final version widely to DoD program managers in May 1987 [Foreman 1987]. As
the technology supporting Ada changed, the information in the document became obsolete. Therefore,
based on requests from a broad constituency, the SEI produced an updated version of the
handbook in 1992 [Hefley 1992].
CMU/SEI-2016-SR-027 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY 33
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