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Optionally Manned Fighting Vehicle: Observations on the Objectivity, Validity, and Reliability of the Army's Report

GAO-23-106549 Published: Jun 27, 2023. Publicly Released: Jun 27, 2023.
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Fast Facts

The Army plans to replace an aging fleet of armored fighting vehicles with the Optionally Manned Fighting Vehicle, which is still in early development. We reviewed the Army's report to Congress on the desired characteristics for the new vehicle and the analyses the Army used to determine those characteristics.

Perspectives from soldiers and vendors contributed to the report's objectivity. However, there weren't enough details to assess its validity or reliability. For example, Army officials said they ensured the models and simulations they used were valid and reliable, but didn't include supporting evidence in the report.

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What GAO Found

In 2018, the Army initiated a program called the Optionally Manned Fighting Vehicle (OMFV) to replace the Bradley Fighting Vehicle. In March 2023, the Army submitted a report to congressional committees about the OMFV. GAO assessed the report for objectivity, validity, and reliability, defining the concepts as follows:

  • Objectivity includes the elimination of biases and clearly defined limitations,
  • Validity includes sound conclusions reasonably derived from methods, and
  • Reliability includes dependable and complete information and data.

Notional Rendering of Optionally Manned Fighting Vehicle

Notional Rendering of Optionally Manned Fighting Vehicle

The Army's report on the desired characteristics of the OMFV presented information that responded to the statutory provision and was generally objective. The Army reported on a range of perspectives by gathering feedback from soldiers and vendors, which contributed to objectivity. However, the Army's report did not include details about the methodologies used or the data collected to allow an assessment of validity and reliability.

The Army presented initial observations on force structure and operational concepts based on studies that were generally objective. For instance, the Army contextualized its findings by reporting on assumptions and limitations. However, the Army's report did not include enough information to draw conclusions regarding the validity and reliability of the force structure and operational concepts analyses completed as of March 2023. The Army noted that it intends to conduct a complete analysis of OMFV force structure and operational concepts over the next 18 to 24 months.

The Army's report also contained information about the combat effectiveness of the OMFV. This information was generally objective in contrasting the three OMFV concepts and Bradley when reporting on desired characteristics such as lethality. This portion of the report did not provide quantitative metrics that would have supported GAO's assessment of the validity of the information. The report also did not present information about data that would have allowed an assessment of their reliability. Army officials said that more details were not included due to security classification.

Why GAO Did This Study

The Army intends to replace the Bradley Fighting Vehicle, which was first produced in the 1980s, with the OMFV. While the Bradley has been modernized with additional capabilities, the OMFV is to achieve greater firepower and mobility with a design that can quickly integrate future upgrades. The Army awarded contracts to five vendors to develop concept designs in September 2021. Congress included a provision in statute for the Army to submit a report on its analysis of OMFV desired characteristics, force structure and operational concepts, and combat effectiveness.

Congress also included a provision in statute for GAO to assess the objectivity, validity, and reliability of the Army's report, among other things. GAO's report assesses the extent to which the Army's report presents an objective, valid, and reliable analysis of (1) the desired characteristics for the OMFV; (2) the force structure designs and operational concepts for the OMFV; and (3) the combat effectiveness of teams equipped with the OMFV compared to those equipped with the modernized Bradley.

GAO defined objectivity, validity, and reliability, and used its generally accepted research standards to assess the extent to which the Army's March 2023 report to congressional committees presented information that generally met these definitions in research design, execution, and reporting. GAO also interviewed Army officials who were involved in developing the report.

For more information, contact Mona Sehgal at (202) 512-4841 or

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