Every two years the NASA Science Mission Directorate (SMD) conducts comparative reviews of operating missions. A Senior Review panel is convened to evaluate the performance of each mission, including its scientific merit, technical status, and cost efficiency. The Astrophysics Division held the 2014 Senior Review in March and April. Three panels were convened to review a) Hubble, b) Chandra, and c) the rest of the operating missions: Fermi, Kepler, MaxWISE, NuSTAR, Planck, Spitzer, Suzaku, Swift, and XMM-Newton.
Swift was ranked first among the nine operating missions in its panel. The Senior Review overall assessment states that "Swift continues to provide unique and exciting science both as stand-alone results and as part of multi-wavelength campaigns. The multitude of science produced with Swift addresses many of the themes and objectives of NASA and Decadal Surveys." The Swift mission is slated to continue through 2018, with the last two years to be reviewed again in 2016.
The panel reports and the NASA response document for the 2014 Senior Review can be found at: http://science.nasa.gov/astrophysics/2014-senior-review-operating-missions/