The report harshly criticizes the program for for failing to use best-practice methodology for its cost and schedule predictions -- warning that NASA's estimated $11.3 billion budget and 2021 unmanned launch deadline may have been informed by unreliable data. The program isn't over budget yet, but it could easily veer off course if NASA doesn't perform a new cost and schedule analysis that falls in-line with best-practice guidelines.
Much of the review reads like a back and forth praise and scolding. The GAO report praises the Orion program for mitigating challenges, such implementing a fix for problems found with the capsule's parachute system, only to then criticize the team for racking up potential cost overruns of $707 million. NASA says it's holding enough of its budget in reserve to cover these kind of unforeseen costs, but the GAO warns that "the program's ability to address other technical issues that may arise with its reserves could be limited."
Moreover, the GAO asserts that NASA aggressive schedule may cause it future delays down the line. In order to keep pace with its 2023 manned launch date, the Orion Program has made a habit of deferring work that increase the risk of straining its budget to a later date -- potentially saddling the project with an unexpected blow to the budget when those tasks are picked up again at the end of the Orion's production cycle. This could increase costs and even cause delays to the planned launch date.
It's not a glowing review, but that doesn't mean the project is doomed. If NASA performs an updated cost and schedule confidence analysis, it can develop a better idea of how deferred work and unexpected challenges will affect the program in the long-term. That's important -- with a new presidential administration on the horizon, NASA may need to defend its budget.