According  to the Army’s force development regulation, the Army seeks to develop a  balanced and affordable force structure that can meet the requirements of  the National Military Strategy and defense planning guidance tasks. Between fiscal year 2011 and fiscal year 2018, the  Army’s planned end strength is projected to decline by 132,000 positions  (12 percent), from about 1.11 million soldiers in fiscal year 2011 to  980,000 soldiers in fiscal year 2018, as shown in figure 1. The Army Prioritized Retaining Combat Units and Plans to Reduce a Greater Proportion of Enabler Units to Make End Strength Reductions

The Army prioritized retaining combat units, as well as other segments of  its force structure, when planning to reduce its end strength to 980,000  soldiers and as a result will take proportionately more position reductions  from its enabler units. Army Prioritized Retaining Combat Units

are responsible for fighting enemy forces in a  contested environment and include the  Army’s Brigade Combat Teams (Armored,  Infantry, and Stryker) and combat aviation  brigades. The Army Plans to Reduce a Greater Proportion of Enabler Units

Given the focus on retaining combat units and the constraints senior  leaders placed on changing the Army’s generating force; its trainees,  transients, holdees, and students accounts; and its reserve components,  the Army will take proportionately more positions from its enabler units  than from its combat units as it reduces end strength to 980,000 soldiers. Army officials told us that, based on senior leaders’ professional military  judgment, concentrating reductions in enabler units is more acceptable  than further reducing the Army’s combat units because combat unit  shortfalls are more challenging to resolve than enabler unit shortfalls. The Army Did Not Comprehensively Assess Mission Risk Associated with Its Planned Force Structure

The Army did not comprehensively assess mission risk (risk to the  missions in DOD’s defense planning guidance) associated with its  planned force structure because it did not assess mission risk for its  enabler units. Army Assessed Mission Risk for Its Combat Forces

In assessing its requirements for aviation brigades and BCTs, the Army  determined where combat units in its planned force structure would be  unable to meet mission requirements given current Army practices in  deploying forces to meet mission demands. Notably, the analysis  assumed that sufficient enabler capability would be available. Army Assessed Risk to the Force for Enabler Units, but Did Not Assess Mission Risk

In contrast to the mission risk assessment the Army conducted for its  combat units (risk to the Army’s ability to meet the missions in DOD’s  defense planning guidance), the Army assessed risk to the force for its  enabler units in its most recent TAA (risk to the health of the Army’s  enabler units). Similarly, the Army assumed that it  could deploy its reserve component enabler units more frequently than  DOD’s current policy allows. Army officials told us that assessing risk to the force for its enablers is  useful because the Army can identify the units it would use the most and  those that it would use least. The Commission recommended  that the Army complete a risk assessment and assess plans and  associated costs of reducing or eliminating these shortfalls. TAA Does Not Routinely Assess Mission Risk for Both Combat and Enabler Force Structure

Army guidance indicates that the Army’s TAA process should assess  mission risk for its combat and enabler force structure, but the Army did  not complete a mission risk assessment during its most recent TAA. According to the Army’s  force development regulation, the Army’s TAA process is intended to  determine the requirements for both the Army’s combat and enabler force  structure to meet the missions specified in defense planning guidance,  document unresourced requirements, and analyze risk given resource  constraints. Without an assessment of the  mission risk associated with the planned enabler force structure  documented in the Army’s October 2015 Army Structure Memorandum,  the Army has an incomplete understanding of the risks that may arise  from the potential shortfalls in its enabler inventory. Furthermore, the Army is required to complete TAA every year and as  currently implemented its TAA process does not include the modeling and  analyses needed to routinely prepare a mission risk assessment for its  combat and enabler force structure. Without expanding the TAA process to routinely  require a mission risk assessment for the Army’s combat and enabler  force structure as part of future iterations of TAA, the Army will continue  to not be well positioned to identify mission risk and develop mitigation  strategies when making future force structure decisions. With respect to our second recommendation that the Army expand its  TAA process to routinely require a mission risk assessment and an  assessment of mitigation strategies for its combat and enabler force  structure, the Army stated that it recognizes the need to routinely conduct  these types of assessments.
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.

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.

What GAO Recommends

GAO recommends that the Army complete a mission risk assessment of its planned enabler force structure, and revise its process to routinely require a mission risk assessment for its combat and enabler force structure. The Army agreed with GAO's recommendations.