Software problems with the FAA's new, $2.1 billion en route automation modernization (Eram) computer system, originally scheduled to be operational at all 20 air route traffic control centers (ARTCC) last year, could incur repair costs for the agency of up to $500 million. In addition, its delivery could be as many as six years late, according to a recent report to Congress from the DOT Inspector General. Built by Lockheed Martin, and described as the "linchpin" of NextGen, Eram is to replace the FAA's Host computer system, which is now more than 30 years old. The FAA formally accepted Eram after initial testing at the agency's Technical Center showed that it met specifications, following which full technical and financial responsibility transferred to the FAA. But in July, the IG reported that subsequent operational testing at the St. Louis ARTCC raised more than 15,000 software issues, requiring a continuing estimated $12 million per month to troubleshoot and repair–at the FAA's expense. The delivery delay would also affect other NextGen elements that interface with Eram, the IG noted. According to deputy FAA Administrator Michael Huerta, "We ran into some operational challenges."