Each key FAA NextGen project has an individual "metric" to measure how its development is progressing. But as the Government Accountability Office (GAO) warned recently, the FAA doesn't use "lateral" metrics that would allow senior management to track the relative progress of separate projects that must eventually work together to make NextGen happen. Without informed management monitoring of the many intertwining NextGen projects, their operational outcomes could be impossible to predict or coordinate, the GAO stated. Similarly, "government acceptance" sounds plain enough, but it isn't, particularly for the FAA's en route automation modernization (Eram), NextGen's future computer backbone. The GAO noted that after limited simulation tests at the FAA Technical Center, the FAA formally accepted Eram from the contractor since the "equipment has performed to specification at all 20 sites." Unfortunately, ARTCC tests with real traffic were abandoned after more than 15,000 software issues arose, of which 1,400 are still unresolved, including 200 "critical" issues. Equally unfortunate, government acceptance means that the FAA will have to pay to fix every one of them, at a cost of $12 million per month, according to the DOT Inspector General. As a result, the FAA is now revising Eram costs and schedule.