Case Study 11: From Columbia Class Submarine, GAO-18-158, December 21, 2017

The Navy’s Columbia class ballistic missile submarines will replace the 14 Ohio class that currently provide the sea-based leg of the U.S. nuclear triad, slated to begin retiring in 2027. The first Columbia must begin patrols in 2031 to prevent a gap in deterrent capabilities; the class will ultimately carry up to 70 percent of the nation’s strategic nuclear capability. The program is a top Navy priority with an expected cost of $267 billion over its life cycle, including $128 billion to research, develop, and buy 12 submarines.

GAO found that additional development and testing were required to demonstrate the maturity of several Columbia class submarine technologies that were critical to performance, including the Integrated Power System, nuclear reactor, common missile compartment, and propulsor and related coordinated stern technologies. As a result, it was unknown whether they would work as expected, be delayed, or cost more than planned. Any unexpected delays could postpone the deployment of the lead submarine past the 2031 deadline.

Further, the Navy underrepresented the program’s technology risks in its 2015 Technology Readiness Assessment (TRA) when it did not identify these technologies as critical. Development of these technologies was key to meeting cost, schedule, and performance requirements. A reliable TRA serves as the basis for realistic discussions on how to mitigate risks as programs move forward from the early stages of technology development. Not identifying these technologies as critical meant Congress may not have had the full picture of the technology risks and their potential effect on cost, schedule, and performance goals as increasing financial commitments were made. The Navy was not required to provide Congress with an update on the program’s progress, including its technology development efforts, until fiscal year 2020—when $8.7 billion for lead ship construction would have already been authorized. Periodic reporting on technology development efforts in the interim could have provided decision-makers assurances about the remaining technical risks as the Navy asked for increasing levels of funding.

Consistent with GAO’s identified best practices, the Navy intended to complete much of the submarine’s overall design prior to starting construction to reduce the risk of cost and schedule growth. However, the Navy awarded a contract for detail design while critical technologies remained unproven—a practice not in line with best practices that led to cost growth and schedule delays on other programs. Proceeding into detail design and construction with immature technologies can lead to design instability and cause construction delays. The Navy planned to accelerate construction of the lead submarine to compensate for an aggressive schedule, which may have led to future delays if the technologies were not fully mature before construction started in 2021.

GAO reported these findings on December 21, 2017 in Columbia Class Submarine: Immature Technologies Present Risks to Achieving Cost, Schedule, and Performance Goals, GAO-18-158.