Army Planning: Comprehensive Risk Assessment Needed for Planned Changes to the Army's Force Structure

What GAO Found

The Army prioritized retaining combat units, such as brigade combat teams (BCT) and combat aviation brigades, when planning to reduce its end strength to 980,000 soldiers, and as a result plans to eliminate proportionately more positions from its support (or “enabler”) units, such as military police and transportation units. The Army's force planning process seeks to link strategy to force structure given available resources through quantitative and qualitative analyses. The Army completed analyses showing that it could reduce its BCTs from 73 in fiscal year 2011 to a minimum of 52 in fiscal year 2017; however, the Army plans to retain 56 BCTs. Moreover, by redesigning its combat units, the Army plans to retain 170 combat battalions (units that fight the enemy)—3 fewer battalions than in fiscal year 2011. Given the focus on retaining combat units, and senior Army leaders' assessment that shortfalls in combat units are more challenging to resolve than shortfalls in enabler units, the Army plans to reduce proportionately more positions from its enabler units than from its combat units.

GAO found that the Army performed considerable analysis of its force structure requirements, but did not assess mission risk for its enabler units.

• Combat Forces: The Army's analysis of BCT requirements entailed an assessment of mission risk—risk resulting from units being unable to meet the missions specified in Department of Defense (DOD) planning guidance. The mission risk assessment used current Army deployment practices and assumed that sufficient enabler forces would be available to sustain combat units over a multi-year scenario. The result of this analysis, and a similar analysis of the Army's aviation brigades, showed that the Army's proposed combat force structure would be sufficient to meet most mission demands.

Enabler Forces: The Army's analysis of its enabler units entailed an assessment of risk to the force—how frequently and for how long units need to deploy to meet as many demands as possible. Army officials said this analysis is useful because it enables the Army to identify the units it would use the most. However, the analysis overstated the availability of the Army's enabler units because it assumed they could deploy more frequently and for longer duration than DOD's policies allow. The Army did not identify enabler unit shortfalls, or the risk those shortfalls pose to meeting mission requirements.

According to Army guidance, the Army's planning process should assess mission risk for both combat and enabler units. The Army did not complete this type of assessment for its enabler units during its most recent force planning process because the Army assessed the risk operational demands pose to the health of the Army's force, not mission risk. Without a mission risk assessment for both the Army's planned combat and enabler force structure, the Army has an incomplete understanding of mission risk and is not well-positioned to develop mitigation strategies. Furthermore, as currently implemented, its process does not include analyses needed for the Army to routinely prepare a mission risk assessment for both its combat and enabler force structure. Without expanding its force planning process to routinely require a mission risk assessment for the Army's combat and enabler force structure as part of future planning processes, the Army will not be well-positioned to comprehensively assess risk and develop mitigation strategies.

Why GAO Did This Study

The Army plans to reduce its end strength to 980,000 active and reserve soldiers by fiscal year 2018, a reduction of nearly 12 percent since fiscal year 2011. According to the Army, this reduction will require reductions of both combat and supporting units. Army leaders reported that reducing the Army to such levels creates significant but manageable risk to executing the U.S. military strategy and that further reductions would result in unacceptable risk.

The Senate report accompanying a bill for the National Defense Authorization Act for Fiscal Year 2015 included a provision that GAO examine the factors that the Army considers and uses when it determines the size and structure of its forces. This report (1) describes the Army's priorities and planned force structure reductions and (2) evaluates the extent to which the Army comprehensively assessed mission risk associated with its planned combat and enabler force structure. GAO examined the Army's force development regulations and process, DOD and Army guidance, and Army analysis and conclusions; and interviewed DOD and Army officials.