The goal of the Spallation Neutron Source (SNS) project was to design, construct, and commission into operation an accelerator-based, pulsed neutron research facility for studies of the structure and dynamics of materials that is substantially better than any other facility in the world. Key requirements, captured in the Level-0 baseline, were to complete a facility capable of >1 MW at a total project cost of $1,411.7M by the end of June 2006. This goal has been not only achieved but exceeded. The SNS construction project was completed in May 2006 at an estimate at completion (EAC) of $1,405.2, meeting all of its performance milestones with a scope that exceeds what was originally envisaged at the time the project was approved.