Air Traffic Control:

Good Progress on Interim Replacement for Outage-Plagued System, but Risks Can Be Further Reduced

AIMD-97-2: Published: Oct 17, 1996. Publicly Released: Oct 17, 1996.

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GAO reviewed the Federal Aviation Administration's (FAA) Display Channel Complex Rehost (DCCR) project, intended as an interim replacementof the Display Channel Complex (DCC), focusing on: (1) recent outages caused by DCC; (2) whether DCC was meeting its system availability requirement; (3) FAA's projections of future DCC outages and availability; and (4) whether FAA was effectively managing the DCCR acquisition to ensure delivery of specified capabilities on schedule and within estimated cost.

GAO found that: (1) DCC, built and deployed over 30 years ago, is critical to FAA's ability to display aircraft situational data in five of FAA's 20 air route traffic control centers; (2) DCC is also responsible for most of the major outages at the five centers from September 1994 through May 1996, accounting for about 48 percent of the total number of major outages and nearly 87 percent of unscheduled system downtime associated with these outages; (3) according to FAA, DCC was able to exceed its availability requirement from fiscal year (FY) 1990 to 1993, on average at the five centers, because of heroic maintenance efforts using "chewing gum and chicken wire"; (4) however, it fell slightly short of the requirement in FY 1994 and 1995, and FAA expects availability to decrease further because of shortages of spare parts and experienced DCC technicians; (5) decreases in DCC availability will result in costly delays for airlines and passengers; (6) FAA has made good progress in acquiring DCCR, but much remains to be accomplished; (7) thus far, the fourth and final DCCR software build is complete, and the number of reported software defects, while cumulatively slightly higher than projections, is showing a favorable trend when adjusted for defect severity; (8) also, FAA is ahead of schedule in completing informal system-level tests, formal testing is generally on schedule, and the first site is ready to begin the system acceptance process; (9) DCCR's development has benefitted from formal risk management and quality assurance programs, and FAA has plans in place to accelerate completion of formal system-level tests; (10) contractor financial reports show that DCCR is under spending estimates; (11) in light of its progress to date, FAA has an opportunity to deliver promised DCCR capabilities on time and within contract budgets; (12) the likelihood of doing so can be increased, however, by acting to mitigate two known risks associated with remaining development activities; (13) specifically, FAA's test plans call for conducting three system-level tests concurrently rather than sequentially, as is normally done; (14) by doing so, FAA expects to implement DCCR early; (15) however, FAA is not formally managing two risks associated with DCCR concurrent testing, which are: (a) staffing three test activities at the same time and thus potentially spreading test personnel too thin; and (b) not defining how it will control and synchronize changes to three system test configurations so as to prevent configuration differences among the three during testing; and (16) by formally managing these risks, FAA will greatly reduce the chances of them impeding future DCCR progress.

Recommendation for Executive Action

  1. Status: Closed - Implemented

    Comments: FAA added contention for human test resources during concurrent test activities, and changed control over system test configuration baselines during concurrent test activities to its formal DCCR risk watch list. GAO confirmed that the risks are now being formally managed.

    Recommendation: To maximize the likelihood of delivering promised DCCR capabilities on time and within contract budgets, the Secretary of Transportation should direct the FAA Administrator to ensure that (1) contention for human test resources during DCCR concurrent test activities, and (2) change control over system test configuration baselines during concurrent test activities, are managed as formal program risks. At a minimum, this formal risk management should include definition, implementation, and tracking of risk mitigation strategies.

    Agency Affected: Department of Transportation


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