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Next Generation Combat Vehicles: As Army Prioritizes Rapid Development, More Attention Needed to Provide Insight on Cost Estimates and Systems Engineering Risks

GAO-20-579 Published: Aug 06, 2020. Publicly Released: Aug 06, 2020.
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Fast Facts

The Army is developing a portfolio of Next Generation Combat Vehicles to provide more firepower, protection, and mobility. The Army's plans for these tanks and other armored vehicles prioritize rapid development. That can limit insight into potential risks.

The Army took some steps to reduce the risks of cost overruns and program delays. But for two of its efforts, the Army didn't fully consider all potential cost uncertainties. It also delayed key engineering reviews for these efforts, increasing the risk of vehicle design problems.

We recommended that the Army follow cost estimating and systems engineering leading practices for these efforts.

Artist Rendering of the Army's Mobile Protected Firepower Vehicle

armored, tracked vehicles

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What GAO Found

The four efforts within the Next Generation Combat Vehicles (NGCV) portfolio all prioritize rapid development, while using different acquisition approaches and contracting strategies. Some of the efforts use the new middle-tier acquisition approach, which enables rapid development by exempting programs from many existing DOD acquisition processes and policies. Similarly, the efforts use contracting strategies that include both traditional contract types as well as more flexible approaches to enable rapid development of technology and designs.

Vehicles of the Next Generation Combat Vehicles Portfolio

Vehicles of the Next Generation Combat Vehicles Portfolio

The two programs within the portfolio that recently initiated acquisitions—Mobile Protected Firepower and Optionally Manned Fighting Vehicle—have taken some steps to mitigate risks in cost and technology consistent with GAO's leading practices. The Army's use of the middle-tier approach for these efforts may facilitate rapid development, but the programs could benefit from additional application of GAO's leading practices. For example, the programs identified some risks in their cost estimates, but because each presented a single estimate of the total cost—referred to as a point estimate—these estimates do not fully reflect how uncertainty could affect costs. Similarly, the programs took some steps to mitigate technical risk by limiting development to 6 years or less and incrementally introducing new technologies, steps consistent with GAO's leading practices. However, by delaying key systems engineering reviews, the programs took some steps not consistent with leading practices, which could increase technical risk. While trade-offs may be necessary to facilitate rapid development, more consistent application of GAO's leading practices for providing cost estimates that reflect uncertainty and conducting timely systems engineering reviews could improve Army's ability to provide insight to decision makers and deliver capability to the warfighter on time and at or near expected costs.

The Army has taken actions to enhance communication, both within the Army and with Department of Defense stakeholders, to mitigate risks. Within the Army, these actions included implementing a cross-functional team structure to collaboratively develop program requirements with input from acquisition, contracting, and technology development staff. Program officials also coordinated with other Army and Department of Defense stakeholders responsible for cost and test assessment, even where not required by policy, to mitigate risk.

Why GAO Did This Study

The Army views the NGCV portfolio as one of its most critical and urgent modernization priorities, as many current Army ground combat vehicles were developed in the 1980s or earlier. Past efforts to replace some of these systems failed at a cost of roughly $23 billion. In November 2017, the Army began new efforts to modernize this portfolio.

GAO was asked to review the Army's plans for modernizing its fleet of ground combat vehicles. This report examines (1) the acquisition approaches and contracting strategies the Army is considering for the NGCV portfolio, (2) the extent to which the Army's efforts to balance schedule, cost, and technology are reducing acquisition risks for that portfolio, and (3) how the Army is communicating internally and externally to reduce acquisition risks.

GAO reviewed the acquisition and contracting plans for each of the vehicles in the portfolio to determine their approaches; assessed schedule, cost, and technology information—where available—against GAO's leading practice guides on these issues as well as other leading practices for acquisition; and interviewed Army and DOD officials.


GAO is making three recommendations, including that the Army follow leading practices on cost estimation and systems engineering to mitigate program risk. In its response, the Army concurred with these recommendations and plans to take action to address them.

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of the Army The Secretary of the Army should direct the MPF program to update its cost estimate to include analyses to support the development of a range of possible cost outcomes for decision makers in a manner consistent with GAO's Cost Estimation Guide. (Recommendation 1)
Closed – Implemented
In June 2022, the MPF program transitioned to the major capability acquisition pathway and updated its life-cycle cost estimate as a part of the decision process for this transition. In August 2023, the Army provided GAO with updated documentation associated with this cost estimate. We assessed this cost estimate and supporting documentation against criteria from GAO's Cost Assessment Guide and found that the risk best practice was substantially met.
Department of the Army The Secretary of the Army should direct the OMFV program to update its cost estimate to include analyses to support the development of a range of possible cost outcomes for decision makers in a manner consistent with GAO's Cost Estimation Guide. (Recommendation 2)
The Army concurred with this recommendation and expects to complete an updated cost estimate in September 2024 that may provide a risk and uncertainty analysis to support a program milestone decision. When we confirm the actions the agency has taken in response to this recommendation, we will provide updated information.
Department of the Army The Secretary of the Army should direct the OMFV program to inform requirements by conducting systems engineering reviews at key decision points consistent with our leading practices for acquisition, as the program office finalizes its acquisition approach. (Recommendation 3)
Closed – Implemented
In May 2021, the Army approved an acquisition strategy for OMFV that plans for a series of systems engineering reviews in advance of multiple key decision points. For example, the strategy lays out a schedule for a system functional review to inform the award of detailed design contracts and a critical design review to inform the transition of OMFV to the prototyping phase as a full program of record, consistent with our leading practices for acquisition.

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Contracting strategiesCost and scheduleCost estimatesDefense acquisition programsMilitary communicationMilitary vehiclesSystems acquisitionSystems designTechnology developmentMilitary forces