A Technical History of the SEI

The benefits of the IMPACT methodology and associated tools to DoD systems were made apparent
in two demonstrations: a phased array radar scheduling demonstration and an embedded avionics
simulation designed to support the F-22 and F-35 JSF programs.
The first demonstration (at the DASADA Demonstration and Exposition in July 2002) showed the
runtime use of Q-RAM. A visual demonstration represented a carrier under attack from a set of
enemy locations. With a variety of threats attacking the ship, the phased-array radar had to be
scheduled in such a way that the ship could destroy those threats. The radar, treated as a nonpreemptible
resource, could be allocated to tracking targets in varying amounts to achieve different
levels of service quality or tracking error [Hansen 2004]. The mission-critical embedded system
demonstration illustrated the use of RTQT to assess the ability of a system to meet the timing
requirements of stochastic task sets (such as mission-awareness applications) under heavy workload
conditions. When RTQT indicates that latency requirements are not met, it provides an engineering
basis for modifying the workload to achieve the desired latency within a specified degree
of certainty.
The Consequence: Bringing an Analytic Basis to Engineering Dynamic
Systems
Work on the F-22 embedded avionics simulation provided new and valuable temporal and performance
analysis information to F-22 designers that was not previously available and that could be
used in the final refinement of the F-22 weapon system. Further, it provided insight into several
design improvements for legacy systems. System utilization, resource efficiency, and maintainability
could be significantly enhanced using DASADA-developed design practices. Progress made
under DASADA allowed LM-Aero and CMU to propose a large-scale DASADA II experiment
centered on upgrading the F-22 mission computer temporal architecture. Results and insights from
this experiment aimed to reduce both new development and application rehost costs through the
analytic composition methodology developed under DASADA I. Additional benefits included enhanced
adaptability to dynamic mission demands, along with increased system reconfiguration
options.
In addition, IMPACT technology was applied in the context of a rotorcraft through collaborations
with U.S. Army Aviation and Missile Command (AMCOM). Investigations into integration of Q-
RAM with hard real-time scheduling in avionics applications under DASADA led to interest in
this technology by the U.S. Army AMCOM. This led to the invitation to join a team to propose a
large-scale DASADA II experiment centered on application of DASADA technologies to the Sikorsky
Black Hawk helicopter.
The SEI Contribution
This research was conducted in collaboration with the Carnegie Mellon faculty and Lockheed
Martin Aeronautics Co. All members of the team made contributions to the IMPACT project.
Since all results are those of the full team, it is not possible to isolate the specific contributions
made by the SEI.
CMU/SEI-2016-SR-027 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY 52
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