The FAA says that the magnitude of software issues with its En Route Automation Modernization (ERAM) program is not as severe as indicated by the Transportation Department’s primary watchdog.

In congressional testimony presented on Sept. 12, DOT Inspector General Calvin Scovel said that controllers and technicians have identified and reported “in excess of 900 new high-priority software issues that need to be addressed” during operational trials at the first nine ERAM sites.

However, the FAA tells AviationWeek that “only a very small percentage of the issues investigated to date on ERAM have been found to be linked to a new software problem.” This proportion is less than 7% of the total.

The 900 issues referred to by the IG were identified by the centers that are running ERAM, but are not necessarily problems with software, the FAA says. Some are site-specific matters, and others are relatively minor concerns prompted by the new look of the system. “When an issue requires a software fix, it is prioritized and scheduled by a team” of personnel from the FAA, Lockheed Martin, and the controllers union, the agency says.

During the Sept. 12 hearing, FAA Acting Administrator Michael Huerta responded to Scovel’s testimony by noting that software issues with ERAM “are certainly not of that magnitude.” He stresses that in any operational system deployment there will be software problems, and “the important thing to focus on is their relative priority and how quickly they can be resolved.”

ERAM is intended to be the core operating system at the FAA’s 20 en route control centers, replacing the 40-year-old Host system. The program began in 2003, but has been beset by severe cost and schedule overruns. It was re-baselined in June 2011.

The FAA has made significant progress this year in ERAM deployment. The system is operating in some capacity at nine centers, with five of those nine using it continuously as their frontline system. The other four are using ERAM for limited periods during the operational trial process. This means the FAA has largely achieved its ERAM goals for the end of the current fiscal year.