Metro unveiled the first 7000-series quad set at Greenbelt on January 6, 2014. The set underwent acceptance testing for at least eight months in order to finalize design specs and work out any problems. In September 2014, Metro reported that it was about one month away from finishing tests on the 7000-series test train, and it stated that it expected an eight-car train made up of 7000-series cars would start carrying passengers in early 2015, and Metro would have 56 railcars by June 2015. During that time, Metro revealed that during testing, a software issue was discovered that it was still addressing, although Metro was confident that the hardware itself was solid. Metro had indicated that the mass production schedule called for 56 new cars to be delivered by June 2015. Combined with the eight cars in the test group, that would give Metro 64 new cars, meaning eight 7000-series trains of eight cars each would be in service next summer. After that, 300 more cars would arrive by February 2017, followed by an additional 100, for a total of 528 new cars at an overall cost of $1.46 billion.