"Boeing has already said it would have to push back its first crewed flights to early 2018. SpaceX has maintained that it would fly by the end of 2017. But the IG investigators weren't buying either of those timetables: "Notwithstanding the contractors' optimism, based on the information we gathered during our audit, we believe it unlikely that either Boeing or SpaceX will achieve certified, crewed flight to the ISS until late 2018."
"Sources at Johnson Space Center, which plays a secondary role in managing the commercial crew program to Kennedy Space Center, have privately told Ars for months that neither Boeing nor SpaceX would fly in 2017. Moreover, these sources have said, it will be fortunate if either company launches test flights, with crew, during the second half of 2018. The key factor to watch now is whether NASA procures additional seats from the Russians to deliver NASA astronauts to the International Space Station in 2019 and beyond."
"Moreover, both companies must satisfy NASA's safety review process to ensure they meet Agency human-rating requirements. As part of the certification process, Boeing and SpaceX conduct safety reviews and report to NASA on potential hazards and their plans for mitigating risks. We found significant delays in NASA's evaluation and approval of these hazard reports and related requests for variances from NASA requirements that increase the risk costly redesign work may be required late in development, which could further delay certification. Although NASA's goal is to complete its review within 8 weeks of receipt of a hazard report, the contractors told us reviews can take as long as 6 months. We also found NASA does not monitor the overall timeliness of its safety review process. Given delays in the Commercial Crew Program, NASA has extended its contract with Roscosmos for astronaut transportation through 2018 at an additional cost of $490 million or $82 million a seat for six more seats. If the Program experiences additional delays, NASA may need to buy additional seats from Russia to ensure a continued U.S. presence on the ISS."