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Report to Congressional Committees: 

United States Government Accountability Office: 

GAO: 

September 2006: 

Defense Transportation: 

Study Limitations Raise Questions about the Adequacy and Completeness 
of the Mobility Capabilities Study and Report: 

Defense Transportation: 

GAO-06-938: 

GAO Highlights: 

Highlights of GAO-06-938, a report to congressional committees 

Why GAO Did This Study: 

The Department of Defense (DOD) issued the Mobility Capabilities Study 
(MCS), which was intended to identify and quantify the mobility 
capabilities needed to support U.S. strategic objectives into the next 
decade. The MCS found that projected capabilities are adequate to 
achieve U.S. objectives with an acceptable level of risk—that is, 
current U.S. inventory of aircraft, ships, prepositioned assets, and 
other capabilities are sufficient, in conjunction with host nation 
support, and assuming planned investments take place. 

The Senate report accompanying the bill for the fiscal year 2005 
Defense Authorization Act required GAO to report on the adequacy and 
completeness of the MCS. GAO assessed the extent to which the MCS met 
generally accepted research standards that this type of study would be 
expected to meet to be considered sound and complete. 

What GAO Found: 

DOD used an innovative approach in conducting the study and 
acknowledged methodological limitations in its report; however, it did 
not fully disclose how these limitations could affect the MCS 
conclusions and recommendations. Therefore, it is not transparent how 
the analyses done for the study support DOD’s conclusions. Measured 
against relevant generally accepted research standards, GAO has 
identified limitations in the MCS and its report that raise questions 
about their adequacy and completeness. GAO suggests that Congress and 
other decision makers exercise caution in using the MCS to make 
investment decisions. Among GAO’s findings:
* Aspects of modeling and data were inadequate in some areas because 
data were lacking and the models used could not simulate all relevant 
aspects of the missions. The report did not explain how these 
limitations could affect the study results or what the impact on 
projected mobility capabilities might be. Generally accepted research 
standards require that models used are adequate for the intended 
purpose, represent a complete range of conditions, and that data used 
are properly generated and complete. For example, the MCS modeled 
hypothetical homeland defense missions rather than homeland defense 
demands derived from a well defined and approved concept of operations 
for homeland defense, because the specific details of the missions were 
still being determined and the data used may be incomplete. The MCS 
also was unable to model the flexible deterrent options/deployment 
order process to move units and equipment into theater because of lack 
of data, but the study assumed a robust use of this process. In 
addition, the MCS report contains over 80 references to the need for 
improved modeling or data.
* While the MCS concluded that combined U.S. and host nation 
transportation assets were adequate, in describing the use of 
warfighting metrics in its analyses, the report does not provide a 
clear understanding of the direct relationship of warfighting 
objectives to transportation capabilities. Additionally, the report 
stated that further analysis is required to understand the operational 
impact of increased or decreased strategic lift on achieving 
warfighting objectives. Relevant generally accepted research standards 
require that conclusions be supported by analyses. The use of both 
warfighting and mobility metrics would allow decision makers to know 
whether combat tasks were achieved and how much strategic 
transportation is needed to accomplish those tasks. 
* In some cases, the MCS results were incomplete, unclear, or 
contingent on further study, making it difficult to identify findings 
and evaluate evidence. Relevant research standards require results to 
be presented in a complete, accurate, and relevant manner. For example, 
the report contains recommendations for further studies and 
assessments, five of which are under way. However, DOD has no plans to 
report the impact of these studies on the MCS results after the studies 
are complete. In addition, the report contains qualified information 
that is not presented clearly, such as varying assessments of intra-
theater assets in three different places. 

What GAO Recommends: 

GAO recommends that the Secretary of Defense, in future mobility s 
capabilities studies beginning with any study currently under way, 
develop models and data for critical missions and processes; include in 
study reports an explanation of how stated limitations might impact 
results; and, incorporate both mobility and warfighting metrics to 
determine capabilities. In comments, DOD concurred with two of the 
recommendations and claimed they did not understand the third, which 
GAO clarified. 

[Hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-06-938]. 

To view the full product, including the scope and methodology, click on 
the link above. For more information, contact William M. Solis at 
(202)512-8365 or solisw@gao.gov. 

[End of Section] 

Contents: 

Letter: 

Results in Brief: 

Background: 

Limitations in the MCS Study and Report Raise Questions about Adequacy 
and Completeness: 

Conclusions: 

Recommendation for Executive Action: 

Agency Comments and Our Evaluation: 

Appendix I: Scope and Methodology: 

Appendix II: Comments from the Department of Defense: 

Appendix III: GAO Contact and Staff Acknowledgments: 

Table: 

Table 1: Generally Accepted Research Standards Relevant to MCS 
Requirements: 

Figure: 

Figure 1: MCS Hypothetical Ongoing Contingencies during 7-year Baseline 
Security Posture Time Frame: 

United States Government Accountability Office: 
Washington, DC 20548: 

September 20, 2006: 

Congressional Committees: 

The National Security Strategy of the United States requires global 
mobility through rapid, effective, and efficient projections of power 
at home and abroad to deploy and sustain America's armed forces. To 
improve its mobility capabilities, the Department of Defense (DOD) 
plans to spend more than $50 billion from fiscal years 2006 through 
2011 for aircraft, ships, ground transportation, prepositioned assets, 
and other mobility assets. DOD has conducted several studies to 
determine mobility requirements and recently completed a study of its 
mobility capabilities and issued a report in December 2005. The intent 
of the Mobility Capabilities Study (MCS) was to identify and quantify 
the mobility capabilities needed to support U.S. strategic objectives 
into the next decade. The MCS determined that the projected mobility 
capabilities are adequate to achieve U.S. objectives with an acceptable 
level of risk during the period from fiscal years 2007 through 2013; 
that is, the current U.S. inventory of aircraft, ships, prepositioned 
assets, and other capabilities are sufficient, in conjunction with host 
nation support. The MCS emphasized that continued investment in the 
mobility system, in line with current departmental priorities and 
planned spending, is required to maintain these capabilities in the 
future. This includes, for example, fully funding Army prepositioned 
assets as planned and completing a planned reengineering of the C-5 
aircraft. The MCS report also made recommendations to conduct further 
studies, develop plans and strategies, and improve data collection and 
mobility models. In fact, DOD officials told us that a Mobility 
Capabilities Study--2006 is underway. 

In the Senate report accompanying the bill for the fiscal year 2005 
Defense Authorization Act, you asked us to monitor the process used to 
conduct the MCS and report on the adequacy and completeness of the 
study.[Footnote 1] Specifically, our objective was to determine whether 
the MCS was adequate and complete. On March 1, 2006, we briefed your 
staff on our preliminary observations. This report expands on that 
briefing and makes recommendations to the Secretary of Defense. 

To conduct our review of the MCS, we analyzed the final MCS report, the 
MCS Terms of Reference and MCS Study Plan, as well as other DOD 
policies and guidance concerning how DOD would conduct the MCS and the 
databases and models used in the study. We identified generally 
accepted research standards that define a sound and complete quality 
study that were relevant to the MCS, and assessed the extent to which 
the MCS report met these standards. We interviewed study officials, 
study participants, and subject matter experts from several DOD 
entities, including the combatant commands and the military services. 
As we monitored the development of the MCS, we requested that DOD 
provide documentation supporting and verifying key analytical and 
decision-making processes.[Footnote 2] DOD officials could not produce 
this documentation during the development of the MCS or following 
issuance of the report. Consequently, we were unable to fully determine 
whether the analytical and decision-making processes that we believe 
are significant to the credibility of the study supported the MCS 
effort and its conclusions. Our scope and methodology are discussed in 
more detail in appendix I. We conducted our work from July 2004 through 
July 2006 in accordance with generally accepted government auditing 
standards. 

Results in Brief: 

DOD used an innovative approach in conducting the study and 
acknowledged some methodological limitations in its report, as any 
sound study should. However, it did not fully disclose how these 
limitations could affect the MCS conclusions and recommendations. 
Therefore, it is not transparent how the analyses done for the study 
support DOD's conclusions. As measured against relevant generally 
accepted research standards, we identified limitations in the MCS study 
and report that raise questions about their adequacy and completeness. 
Among our findings: 

* Aspects of modeling and data were inadequate in some areas because 
data were lacking and some of the models used could not simulate all 
relevant aspects of the missions. The report did not explain how these 
limitations could affect the study results or what the effect on the 
projected mobility capabilities might be. Relevant research standards 
require that models used are adequate for the intended purpose, 
represent a complete range of conditions, and that data used are 
properly generated and complete. For example, the MCS modeled 
hypothetical homeland defense missions rather than homeland defense 
demands derived from a well defined and approved concept of operations 
for homeland defense, because the specific details of the missions were 
still being determined, and DOD acknowledged that the data used may be 
incomplete. The MCS also was unable to model the flexible deterrent 
options/deployment order process to move units and equipment into 
theater due to lack of data, but the study assumed a robust use of this 
process, which in one scenario accounted for approximately 60 percent 
of the airlift prior to beginning combat operations.[Footnote 3] In 
addition, the MCS report contains more than 80 references to the need 
for improved modeling, and 12 of these references call for additional 
data or other refinements. Additionally, the MCS modeled the year 2012 
to determine the transportation capabilities needed for the years 2007 
through 2013. The year 2012 did not place as much demand for mobility 
assets in support of smaller military operations, such as peacekeeping, 
as other years. However, DOD officials considered 2012--the year 
modeled--as "most likely" to occur and stated that statistically it was 
not different from other years in the 2007 to 2013 period even though 
the number of smaller military operations is the least of any of the 
years reviewed. 

* While the MCS concluded that combined U.S. and host nation 
transportation assets were adequate to meet U.S. objectives with 
acceptable risk, the report, in describing the use of warfighting 
metrics in its analyses, does not provide a clear understanding of the 
direct relationship of warfighting objectives to transportation 
capabilities. Acknowledging this point, the report stated that further 
analysis is required to understand the operational impact of increased 
or decreased strategic lift on achieving warfighting objectives. 
Relevant generally accepted research standards require that conclusions 
be supported by analyses. The use of warfighting metrics is a measure 
to determine whether combat tasks, such as achieving air superiority, 
are achieved. However, they do not measure whether appropriate 
personnel, supplies, and equipment arrived in accordance with 
timelines. As a result, we could not determine how the study concluded 
that planned transportation assets were adequate because the study did 
not contain a transparent analysis to support its conclusion or a clear 
roadmap in the report to help decision makers understand what that 
conclusion meant in terms of type and number of mobility assets needed. 
Previous DOD mobility studies primarily used mobility metrics, which 
measured success in terms of tons of equipment and personnel moved per 
day to accomplish military objectives. The use of both warfighting and 
mobility metrics to measure success would allow decision makers to know 
whether combat tasks were achieved and how much strategic 
transportation is needed to accomplish those tasks. 

* In some cases, the MCS results were incomplete, unclear, or 
contingent on further study, making it difficult to identify findings 
and evaluate evidence. Relevant research standards require results to 
be presented in a complete, accurate, and relevant manner. For example, 
the report contains several recommendations for further studies and 
assessments, five of which are under way. However, DOD has no plans to 
report the effect of these studies on the MCS results after the studies 
are complete. In addition, the report contains qualified information 
that is not presented clearly, such as varying assessments of 
intratheater assets in three different places in the report. The lack 
of clarity and conciseness of the reported results can limit the 
study's usefulness to decision makers and stakeholders. 

* Verification, validation, and accreditation (VV&A) of models and data 
used to conduct the study was not complete because it was not done in 
accordance with DOD policy or relevant research standards. Moreover, 
relevant research standards state that a study report should include a 
VV&A accreditation report that is signed by the study director and 
addresses the models and data certification. DOD officials acknowledged 
that they did not comply with DOD VV&A policy when using legacy models 
in the MCS because they contended that long-term use of models and data 
constitutes an equivalent VV&A process. Other than a description of the 
process contained in the MCS report, DOD officials could provide no 
additional documentation to verify and validate this equivalent process 
to provide the assurance that models and data used in the MCS reduced 
the risk inherent in modeling and simulation and added to the 
credibility of the results. Moreover, officials could not provide 
documentation to support key analytical and decision-making processes 
used by senior DOD leadership, thus undermining the credibility of the 
reported study results. 

These limitations to the study's methodology raise questions concerning 
the accuracy of the study's finding that projected capabilities are 
adequate to achieve U.S. objectives with an acceptable level of risk. 
Until DOD conducts an adequate and complete future MCS and clearly 
discloses all limitations and their effects on the study results, 
decision makers may be unable to clearly understand the operational 
implications of the study results and make fully informed programmatic 
investment decisions concerning mobility capabilities. We are 
recommending that the Secretary of Defense, when conducting future 
mobility capabilities studies, beginning with any study currently under 
way, develop and use models and data for critical missions and 
processes that are verified, validated, and accredited as required; 
include in study reports an explanation of how stated limitations might 
impact the study results and, at a minimum, describe how recommended 
future studies might be conducted to enhance the results of the 
original study; and incorporate both mobility and warfighting metrics 
in determining capabilities. 

In commenting on a draft of this report, DOD concurred with the first 
and third recommendations and claimed that they did not understand the 
second. We have clarified that recommendation to the Secretary of 
Defense to include in study reports an explanation of how stated 
limitations might impact the study results and, at a minimum, describe 
how recommended future studies might be conducted to enhance the 
results of the original study. In its comments, DOD also stated that 
the report contained misleading information and factual errors. We 
disagree with DOD's assertion. We did modify our report to respond to a 
DOD technical comment related to homeland defense missions. DOD's 
comments and our evaluation of them are discussed in the agency 
comments section of this report. 

Background: 

The MCS was the first assessment of DOD's mobility system since 2000. 
The study was designed to identify changes in DOD's transportation 
force structure due to changes in threats and national security and 
military strategies. The MCS is the fourth in a series of major 
mobility studies that DOD has conducted since the end of the Cold War. 
The first study, the Mobility Requirements Study, conducted in 1992, 
was undertaken because of concern about the DOD's strategic mobility 
capabilities in the wake of Operation Desert Shield and Operation 
Desert Storm. That study established mobility requirements for the post-
Cold War era; defined baseline requirements for intertheater, or 
strategic, mobility; and proposed a long-range investment plan to meet 
these requirements. The Mobility Requirements Study Bottom-Up Review 
Update, conducted in 1994, reaffirmed the need for increases in key 
mobility components and validated the prior study's recommendation for 
the procurement of additional ships for afloat prepositioning and for 
surge deployments of forces based in the continental United States. The 
Mobility Requirements Study--2005, issued in 2001, projected future 
mobility requirements based on two nearly simultaneous major regional 
contingencies. It included a broader range of factors, including host 
nation support and enemy use of weapons of mass destruction, than the 
previous studies. 

The current MCS, which began in May 2004, reassessed DOD's mobility 
capabilities against the backdrop of a revised National Military 
Strategy that included the ongoing war against violent extremism, an 
evolving global defense posture, a new force-sizing construct, revised 
campaign scenarios, and ongoing departmentwide transformation efforts. 
The study results were intended to support decisions on future 
strategic airlift, aerial refueling aircraft, and sealift procurements 
needed to meet varying military requirements. The study used an 
innovative "capabilities-based" approach, measuring existing and 
currently projected mobility capabilities against warfighting demands 
that could be expected in fiscal year 2012 while also considering 
mobility demands during the 7-year period from fiscal year 2007 through 
fiscal year 2013. According to DOD officials, the Secretary of Defense 
believed this approach would give him greater flexibility in deciding 
which capabilities to fund in a constrained budget environment. In 
considering each aspect of the National Military Strategy,[Footnote 4] 
the MCS modeled warfighting scenarios in the year 2012 using different 
premises with varying assumptions to develop and evaluate mobility 
capability mix alternatives. The models were used to evaluate 
transportation alternatives, including variations in alternative 
transportation modes (air, land, sea) and sources (military, civilian, 
foreign), as well as factors that affect transportation mode and source 
decisions. The scope of the MCS described the study as an assessment of 
the full range of transportation needs required to support (1) combat 
operations; (2) smaller military efforts, such as peacekeeping or 
overseas evacuation of American citizens; (3) homeland defense/civil 
support, such as disaster relief and antiterrorism response; and (4) 
other strategic missions, such as strategic nuclear and global strike 
missions. The study was coauthored by the Office of the Secretary of 
Defense, Office of the Director, Program Analysis and Evaluation 
(PA&E), and the Chairman, Joint Chiefs of Staff, Office of the Director 
of Logistics. Other DOD components involved in the study included the 
U.S. Transportation Command and its subordinate commands, the Office of 
the Under Secretary of Defense (Acquisition, Technology and Logistics), 
the combatant commanders, the military services, and others. The final 
report was signed on December 19, 2005, by the Deputy Secretary of 
Defense. 

Limitations in the MCS Study and Report Raise Questions about Adequacy 
and Completeness: 

As measured against relevant generally accepted research standards, 
limitations in the MCS study and report raise questions about their 
adequacy and completeness. For example, aspects of modeling and data 
were inadequate in some areas because data were lacking and some of the 
models used could not simulate all relevant aspects of the missions. 
Furthermore, the exclusive use of warfighting metrics in the MCS 
analyses limited the usefulness of the report. Moreover, in some cases 
the MCS results were incomplete, unclear, or contingent on further 
study, making it difficult to identify findings and evaluate evidence. 
Finally, verification, validation, and accreditation of models and data 
used to conduct the study were incomplete because they were not done in 
accordance with DOD policy or relevant research standards, and 
supporting documentation for key processes could not be provided. 

Aspects of Modeling and Data Were Inadequate: 

Aspects of modeling and data were inadequate in some areas because data 
were lacking and some of the models used could not simulate all 
relevant aspects of the missions. Relevant research standards require 
that models used are adequate for the intended purpose, represent a 
complete range of conditions, and that data used are properly generated 
and complete. As DOD acknowledged in the MCS report as a study 
limitation, some modeling tools were not available to analyze key 
missions. The MCS cited deficiencies in several existing mobility 
models and the need for follow-on MCS analyses. The MCS report also 
acknowledged that the identified deficiencies in data hindered analysis 
of future requirements and transportation system performance. However, 
the report did not explain how these limitations could affect the study 
results or what the effect on the projected mobility capabilities might 
be. 

For example, the MCS modeled hypothetical homeland defense missions 
rather than homeland defense demands derived from a well defined and 
approved concept of operations for homeland defense, because the 
specific details of the missions were still being determined, and DOD 
acknowledged that the data used are incomplete. The MCS report 
recommended further analysis of mobility capabilities after homeland 
defense needs are refined. However, the report did not identify the 
potential effect that using these hypothetical scenarios might have on 
the MCS results. The MCS also was unable to model the flexible 
deterrent options/deployment order process to move units and equipment 
into theater because of lack of data on how deployment orders have been 
issued in the past for major combat operations. However, the MCS 
assumed a robust use of the flexible deterrent option/deployment order 
process, which in one scenario accounted for approximately 60 percent 
of the early airlift movement prior to the beginning of combat 
operations. Instead, the MCS modeled the flow of forces and equipment 
contained in the time-phased force deployment data process.[Footnote 5] 
Based on the scenarios provided for the MCS analyses, we could not 
determine how the deployment order process would affect the mobility 
assets required for major combat operations. The MCS report noted that 
additional analysis is required to determine the implications of the 
deployment order process and to provide sufficient information for 
decision makers concerning the amount of future mobility assets 
actually needed. 

In addition to these modeling and data issues, the MCS report contains 
more than 80 references to the need for improved modeling, and 12 of 
these references call for additional data or other refinements, such as 
follow-on analyses, further assessments, future evaluations, additional 
study, and investigation of alternatives in a wide range of areas, such 
as antiterrorism response, infrastructure availability, intratheater 
airlift, strategic sealift, air refueling, and availability of civil 
reserve aircraft. Some of these studies are currently underway, as 
discussed later in this report. 

Moreover, our analysis of the MCS report showed that the year modeled 
(2012) to determine the DOD transportation capabilities needed for the 
years 2007 through 2013 did not place as much demand for mobility 
assets in support of smaller military operations, such as peacekeeping, 
as other years. To establish transportation demands for mission 
requirements, DOD developed and used a baseline security 
posture[Footnote 6] that covered a 7-year period. This baseline was 
developed, in part, using a historical analysis of DOD's movement of 
personnel, equipment, supplies, and other items. According to DOD 
officials, Office of the Under Secretary of Defense for Policy, which 
developed the baseline security posture, selected the year modeled in 
the MCS because it was deemed the "most likely" to occur in terms of 
transportation demands and because it was not statistically different 
from other years in the 7-year period. However, our analysis showed 
that 2012 involved the least demand for transportation assets in 
support of smaller military efforts than any year in the 7-year period 
and did not fully stress the defense transportation system. Figure 1 
depicts the number of hypothetical ongoing contingencies for each year 
in the baseline as shown in the MCS. 

Figure 1: MCS Hypothetical Ongoing Contingencies during 7-year Baseline 
Security Posture Time Frame: 

[See PDF for image] 

Source: GAO's analysis of MCS notional lesser contingency schedule. 

Note: A particular contingency may be ongoing in more than 1 year. Each 
contingency has unique cargo and passenger requirements. For example, a 
contingency that may be ongoing over a 2-or 3-year time frame may 
require more or less mobility capability than a 6-month contingency. 

[End of figure] 

Although not transparent in the study, DOD officials said scenarios in 
the year modeled were not intended to fully stress the defense 
transportation system. DOD officials provided no further explanation 
for the year selected to develop the DOD transportation capabilities 
other than it was directed by Office of the Under Secretary of Defense 
for Policy and agreed to by the study leadership. We believe that 
selection of a different year that placed an increased demand on 
transportation assets for smaller military efforts may have revealed 
gaps in mobility requirements. Therefore, we found that the selection 
of 2012 as the modeling year was a limitation in the MCS with respect 
to smaller military efforts. 

Because of these modeling and data limitations, the MCS may have 
incorrectly estimated the future mobility requirements needed to 
support homeland defense missions, major combat operations, and smaller 
contingencies. Until DOD improves aspects of the modeling and data used 
to conduct the MCS--to include defining its homeland defense mission 
needs, developing models for the deployment order process, and 
explaining how identified modeling and data limitations could affect 
the study results--decision makers may not have adequate and complete 
information about DOD's mobility capabilities. 

Exclusive Use of Warfighting Metrics in MCS Analyses Limited Usefulness 
of Report: 

While the MCS concluded that combined U.S. and host nation 
transportation assets were adequate to meet U.S. objectives with 
acceptable risk, the report, in describing the use of warfighting 
metrics in its analyses, does not provide a clear understanding of the 
direct relationship of warfighting objectives to transportation 
capabilities. The report acknowledged that further analysis is required 
to understand the operational impact of increased or decreased 
strategic lift on achieving warfighting objectives. Relevant generally 
accepted research standards require that conclusions be supported by 
analyses. The use of warfighting metrics is a measure to determine 
whether combat tasks, such as establishing air superiority, are 
achieved. However, they do not measure success in terms of whether 
appropriate personnel, supplies, and equipment arrived in accordance 
with timelines. As a result, we could not determine how the study 
concluded that planned transportation assets were adequate because the 
study did not contain a transparent analysis to support its conclusion. 
In our opinion, it is important for decision makers to have an 
understanding of both combat tasks that must be achieved and the amount 
of transportation assets needed to achieve those tasks with some level 
of success. This understanding would allow creation of a clear roadmap 
for investment decisions. However, we could not determine how the study 
calculated the specific numbers of transportation assets needed or 
whether there are specific gaps, overlaps, or excesses in 
transportation assets, a key objective of the study. Previous DOD 
mobility studies, including the Mobility Requirements Study--2005, 
primarily used mobility metrics, which measured success in terms of 
tons of equipment and personnel moved per day to accomplish military 
objectives. Million-ton-miles per day is a commonly accepted measure of 
airlift performance and reflects how much cargo can be delivered over a 
given distance in a given period of time based on the capability of 
each type of aircraft. A similar mobility metric--short tons--is used 
to measure ship capability. However, these studies did not fully 
integrate combat tasks as a metric. The use of both warfighting and 
mobility metrics to measure success would allow decision makers to know 
whether there is sufficient capability to achieve warfighting 
objectives, as well as to understand the number, type, and mix of 
mobility assets that are actually needed. 

Results Are Not Always Complete or Presented Clearly and Are Qualified 
or Contingent on Further Study or Analysis: 

In some cases, the MCS results were incomplete, unclear, or contingent 
on further study, making it difficult to identify findings and evaluate 
evidence. Relevant research standards require results to be presented 
in a complete, accurate, and relevant manner; conclusions to be sound 
and complete; and recommendations to be supported by analyses. Our 
analysis of the MCS report found that it contains several 
recommendations for further studies and assessments, five of which are 
under way. The five studies address intratheater lift capabilities; 
sealift petroleum, oil, and lubricants; logistics contingency 
operations capabilities; aerial refueling; and integrated global 
presence and basing. However, the report does not explain the potential 
effect of these ongoing studies on the MCS results after the studies 
are complete, nor does DOD have plans to report the effect of these 
studies on the MCS results. 

In addition, the report contains qualified information that is not 
presented clearly in the report, such as varying assessments of 
intratheater assets in three different places. For example, the report 
states in the assessment section of the executive summary that 
projected transportation assets are sufficient to address intratheater 
demands in the fiscal years 2007 through 2013 time frame. However, in 
the recommendations section of the executive summary, the report states 
that DOD should take action to determine the proper mix of intratheater 
assets needed to meet requirements. Then, in the part of the report 
that discusses intratheater airlift, the report states that a detailed 
analysis of intratheater airlift needs would require improved modeling 
tools to accurately capture interactions among land, sealift, and 
airlift capabilities and that data sets must be developed that 
accurately describe the requirement in light of emerging concepts. 

VV&A of Models and Data Was Not Complete: 

VV&A of models and data used to conduct the study was not complete 
because it was not done in accordance with DOD policy or relevant 
research standards. DOD policy issued by the Under Secretary of Defense 
for Acquisition, Technology and Logistics requires that DOD models and 
data go through a VV&A process. Moreover, relevant research standards 
state that a study report should include a VV&A accreditation report 
that is signed by the study director and addresses the models and data 
certification. DOD officials acknowledged that they did not comply with 
the VV&A policy when using legacy models in the MCS because they 
believed such an approach was not warranted for legacy models that have 
been used for many years and have proved reliable. Moreover, these 
officials believe that such long-term use constitutes a VV&A process 
equivalent to that required in the policy. However, the DOD policy does 
not specify that the actual use of a model constitutes an equivalent 
VV&A process. VV&A of models and data reduces the risk inherent in the 
use of models and simulations by improving the credibility of modeling 
and simulation results. We previously reported our concerns that DOD 
did not follow its policy in executing the MCS and had little 
documentation to support the VV&A process used.[Footnote 7] We found 
that the final MCS report contained a description of the equivalent 
VV&A process, but DOD officials could provide no further documentation 
to verify and validate this equivalent process other than the 
description included in the report. We also found no documentation in 
the study report to support DOD claims that the models have proven 
reliable. 

Furthermore, DOD officials were unable to provide documentation to 
support and verify key analytical and decision-making processes used by 
senior DOD leadership throughout the study. Relevant research standards 
support documenting the study's analytical and decision-making 
processes to ensure the accuracy, completeness, and credibility of 
study results. DOD officials told us that the study's key analytical 
and decision-making processes were validated and approved by study 
participants during working group meetings and by senior leadership 
during General Officer Steering Committee meetings and Executive 
Committee meetings. PA&E officials could not produce documentation of 
these meetings because they said documentation did not exist. Nor could 
they produce other documents we requested during the development of the 
MCS or following issuance of the report. Consequently, we were unable 
to determine the adequacy and completeness of the analytical and 
decision-making processes that supported the MCS effort and that we 
believe are significant to the credibility of the study and its 
conclusions. 

Conclusions: 

The methodological limitations in the MCS that we identified--some of 
which were acknowledged by DOD in the MCS report--raise questions about 
the adequacy and completeness of the study and its report. Until DOD 
improves aspects of the modeling and data used to conduct the MCS--such 
as defining its homeland defense mission needs and developing models 
for the deployment order process--decision makers may not have adequate 
and complete information about DOD's mobility capabilities to enable 
them to make fully informed investment decisions. Furthermore, in the 
absence of an explanation of how identified modeling and data 
limitations could affect the study results or how such limitations 
could affect projected mobility capability requirements, the accuracy 
of the study's finding that projected capabilities are adequate to 
achieve U.S. objectives with an acceptable level of risk during the 
period from fiscal years 2007 through 2013 is unclear. Moreover, 
without a transparent comparison between existing mobility assets and 
projected needed assets, decision makers will be unable to use study 
results to identify and quantify the specific types and mix of mobility 
assets needed to address mobility gaps, overlaps, and excesses. Until 
DOD conducts an adequate and complete future MCS and clearly discloses 
all limitations and their effects on the study results, decision makers 
likely will not have full information concerning DOD's mobility 
capabilities. As a result, we suggest that Congress and other decision 
makers exercise caution in using the MCS to make programmatic 
investment decisions. 

Recommendation for Executive Action: 

To provide decision makers with adequate and complete information 
concerning mobility capabilities so they are able to clearly understand 
the operational implications of the study and make fully informed 
programmatic investment decisions, and to improve the usefulness of 
future mobility capabilities studies, we recommend that the Secretary 
of Defense take the following three actions, when conducting future 
mobility capabilities studies beginning with any study currently 
underway: 

* develop models and data for all critical missions, such as homeland 
defense, and processes, such as the flexible deterrent options/ 
deployment order process; 

* include in study reports an explanation of how stated limitations 
might impact the study results and, at a minimum, describe how 
recommended future studies might be conducted to enhance the results of 
the original study; and: 

* incorporate both mobility and warfighting metrics in determining 
capabilities. 

Agency Comments and Our Evaluation: 

In commenting on a draft of this report, DOD concurred with our first 
and third recommendations. DOD stated it did not understand our second 
recommendation that the Secretary of Defense, when conducting future 
mobility studies, beginning with any study currently underway, include 
in study reports an explanation of how ongoing and follow-on studies 
and modeling and data limitations that are referenced in the report 
could affect the reported results. DOD also noted that it plans to 
continue its ongoing efforts to enhance the models and data collection 
processes used to assess mobility capabilities across the full range of 
strategic missions and supports the notion that continual improvements 
are needed. As we noted throughout our report, the MCS report contains 
numerous and repeated references to the need for improved modeling and 
additional data or other refinements, such as follow-on analyses, 
further assessments, future evaluations, additional study, and 
investigation of alternatives in a wide range of areas. DOD further 
commented that while a completed study can recommend that follow-on 
studies be conducted, it cannot explain how future studies might affect 
the results of the current study. We acknowledge that DOD cannot 
quantitatively predict the outcome of an ongoing or future study. 
However, we believe DOD should be able to explain what ongoing follow- 
on studies or evaluations seek to determine, what changes are being 
made to the data inputs and modeling tools that are being used to 
conduct the studies, and how DOD expects the results may differ from 
current study results. While the explanation may be hypothetical, as 
are many operations research study hypotheses, it can provide decision 
makers with a better understanding of the current study's limitations 
and results and how an ongoing or future study's results may differ. 
Therefore, we refined our recommendation to recommend that the 
Secretary of Defense, when conducting future mobility studies, 
beginning with any study currently under way, include in study reports 
an explanation of how stated limitations might impact the study results 
and, at a minimum, describe how recommended future studies might be 
conducted to enhance the results of the original study. For example, if 
modeling and data are limitations to a study, the report should discuss 
the ways in which the results might change with better models and data. 

DOD also commented that our report contained misleading information and 
factual errors and that it stands by the adequacy and completeness of 
the MCS. The department provided examples in its technical comments 
where it believed our report contained misleading information and 
factual errors. We disagree with the department's comments regarding 
the facts in our report and have addressed each of the department's 
comments in appendix II. 

Lastly, DOD stated that the MCS and its conclusions are well accepted 
by the civilian and military leadership of the department, and pointed 
out that in March 2006 testimony before the House Armed Services 
Committee, the Commander, U.S. Transportation Command, stated that the 
planned strategic airlift fleet determined by the MCS is "about the 
right capacity". However we note that in the same hearing, the 
Commander also stated that he thought DOD needed "somewhere in the 
neighborhood of" 20 C-17 cargo aircraft beyond what is planned. We also 
note that in the Commander's April 2006 testimony before the Senate 
Armed Services Committee, Subcommittee on Sealift, he stated that, in 
an internal Focused Mobility Analysis to study strategic mobility from 
a Transportation Command perspective, the MCS will be the baseline, 
"but we will explore how changes in key assumptions may impact the 
analytical outcome." 

We are sending copies of this report to the Secretary of Defense; the 
Director of PA&E; and the Office of the Chairman, Joint Chiefs of 
Staff. We will also make copies available to others upon request. In 
addition, the report is available at no charge on the GAO Web site at 
[Hyperlink, http://www.gao.gov]. If you or your staff have any 
questions regarding the briefing or this report, please contact me at 
(202) 512-8365 or solisw@gao.gov. Contact points for our Offices of 
Congressional Relations and Public Affairs may be found on the last 
page of this report. GAO staff who made key contributions to this 
report are listed in appendix III. 

Signed by: 

William M. Solis: 
Director, Defense Capabilities and Management: 

List of Congressional Committees: 

The Honorable John Warner: 
Chairman: 
The Honorable Carl Levin: 
Ranking Minority Member: 
Committee on Armed Services: 
United States Senate: 

The Honorable Ted Stevens: 
Chairman: 
The Honorable Daniel K. Inouye: 
Ranking Minority Member: 
Subcommittee on Defense: 
Committee on Appropriations: 
United States Senate: 

The Honorable Duncan L. Hunter: 
Chairman: 
The Honorable Ike Skelton: 
Ranking Minority Member: 
Committee on Armed Services: 
House of Representatives: 

The Honorable C.W. Bill Young: 
Chairman: 
The Honorable John P. Murtha: 
Ranking Minority Member: 
Subcommittee on Defense: 
Committee on Appropriations: 
House of Representatives: 

[End of section] 

Appendix I: Scope and Methodology: 

To conduct our review of the Mobility Capabilities Study (MCS), we 
reviewed and analyzed the final MCS report; the MCS Terms of Reference; 
the MCS Study Plan; applicable Department of Defense (DOD) strategic 
planning guidance; as well as other DOD guidance, directives, 
instructions, and memos that describe how DOD would conduct its MCS. We 
also reviewed the National Security Strategy of the United States of 
America and the National Military Strategy of the United States of 
America; DOD guidance concerning data collection, development, and 
management in support of strategic analysis; DOD modeling and 
simulation instruction; Defense Modeling and Simulation Office 
guidance; descriptions of models used to conduct the study; and the 
databases used in the models. We interviewed study officials from the 
Office of the Secretary of Defense, Program Analysis and Evaluation 
(PA&E), and the office of the Chairman, Joint Chiefs of Staff, 
Logistics, as well as study participants and subject matter experts 
from the U.S. Transportation Command, Air Mobility Command, Surface 
Deployment and Distribution Command, the combatant commands, and the 
military services concerning the extent of their input to the study. We 
also interviewed officials from the Office of the Secretary of Defense, 
Acquisition, Technology and Logistics, and the Modeling and Simulation 
Technical Director at the Defense Modeling and Simulation Office. 

Additionally, we reviewed research literature and DOD guidance and 
identified frequently occurring, generally accepted research standards 
that are relevant for defense studies such as the MCS that define a 
quality or sound and complete study. The following were our sources for 
these standards: 

* GAO, Government Auditing Standards: 2003 Revision, GAO-03-673G 
(Washington, D.C.: June 2003); 

* GAO, Designing Evaluations, GAO/PEMD-10.1.4 (Washington, D.C.: March 
1991); 

* GAO, Dimensions of Quality, GAO/QTM-94-1 (Washington, D.C.: February 
2004); 

* RAND Corporation, RAND Standards for High-Quality Research and 
Analysis (Santa Monica, Calif.: June 2004); 

* Air Force Office of Aerospace Studies, Analysts Handbook: On 
Understanding the Nature of Analysis (January 2000); 

* Air Force, Office of Aerospace Studies, Air Force Analysis Handbook, 
A Guide for Performing Analysis Studies: For Analysis of Alternatives 
or Functional Solution Analysis (July 2004); 

* Department of Defense, DOD Modeling and Simulation (M&S) 
Verification, Validation, Accreditation (VV&A), Instruction 5000.61 
(Washington, D.C.: May 2003); 

* Department of Defense, Data Collection, Development, and Management 
in Support of Strategic Analysis, Directive 8260.1 (Washington, D.C.: 
December 2, 2003); and: 

* Department of Defense, Implementation of Data Collection, 
Development, and Management for Strategic Analyses, Instruction 8260.2 
(Washington, D.C.: January 21, 2003). 

During the process of identifying generally accepted research standards 
we noted that not all studies are conducted the same way. For example, 
while all studies use data, not all use baseline data. Likewise, all 
studies require analyses, but not all use models or simulation to 
conduct analyses. We tailored the research standards we identified as 
relevant to the MCS, as shown in table 1. 

Table 1: Generally Accepted Research Standards Relevant to MCS 
Requirements: 

Design: The Study is well designed: 
I; Design: The Study is well designed: Study plan, scope, and 
objectives follow Defense Planning Guidance. 
I.a; Design: The Study is well designed: (Do the study scope and 
objectives fully address the charter presented in the 2004 Defense 
Planning Guidance?). 
I.a.1; Design: The Study is well designed: Does the study plan address 
specified guidance?. 
I.b; Design: The Study is well designed: Was the study plan followed?. 
I.c; Design: The Study is well designed: Were deviations from the study 
plan explained and documented?. 
I.d; Design: The Study is well designed: Was the study plan updatedover 
the course of the study and the updates explicitly identified in the 
study and updated study plan?. 

II; Design: The Study is well designed: Assumptions and constraints are 
reasonable and consistent: 
II.a; Design: The Study is well designed: Are assumptions and 
constraints explicitly identified?. 
II.a.1; Design: The Study is well designed: (Are the study assumptions 
necessary and reasonable?). 
II.b; Design: The Study is well designed: Do the study assumptions 
support a sound analysis?. 
II.c; Design: The Study is well designed: Are the assumptions used in 
analyses common throughout the study and models?. 
II.d; Design: The Study is well designed: Do the assumptions contribute 
to an objective and balanced research effort?. 

III; Design: The Study is well designed: Scenarios and threats are 
reasonable: 
III.a; Design: The Study is well designed: Are scenarios traceable back 
to formal guidance?. 
III.b; Design: The Study is well designed: Were the threat scenarios 
validated and Defense Intelligence Agency approved and documented?. 
III.c; Design: The Study is well designed: Do scenarios represent a 
reasonably complete range of conditions?. 
III.d; Design: The Study is well designed: (Were the threats varied to 
allow for the conduct of sensitivity analysis?). 

Execution: The study is well executed. 

IV; Design: The Study is well designed: Methodology is successfully 
executed: 
IV.a; Design: The Study is well designed: Was the study methodology 
executed consistent with the (MCS) study plan and schedule?. 
IV.b; Design: The Study is well designed: (Does the methodology support 
accomplishing the objectives presented in the study plan?). 
IV.c; Design: The Study is well designed: Were the models used to 
support the analyses adequate for their intended purpose?. 
IV.d; Design: The Study is well designed: Were the model input data 
properly generated to support the methodology?. 

V; Design: The Study is well designed: (Analytical ) Baseline data and 
other data used to support study and analyses validated, verified, and 
approved: 
V.a; Design: The Study is well designed: Is the (analytical) baseline 
fully and completely identified and used consistently throughout the 
study for the various analyses?. 
V.b; Design: The Study is well designed: Were data limitations 
identified (and the impact of the limitations fully explained?). 
V.c; Design: The Study is well designed: Were the (baseline security 
posture) data verified and validated?. 
V.d; Design: The Study is well designed: Was the data verification and 
validation process documented?. 

VI; Design: The Study is well designed: Models, simulations, and 
verification, validation, and accreditation are reasonable: 
VI.a; Design: The Study is well designed: Was a VV&A accreditation 
report that addresses the models and data certification signed by the 
study director and included in the report?. 
VI.b; Design: The Study is well designed: Were modeling and simulation 
limitations identified and explained?. 
VI.c; Design: The Study is well designed: Has each model in the study 
been described?. 
VI.d; Design: The Study is well designed: Are the model processes 
clearly explained, documented and understood?. 

VII; Design: The Study is well designed: Measures of effectiveness 
(MOEs) and essential elements of analysis (EEAs) are addressed: 
VII.a; Design: The Study is well designed: (Do MOEs adhere to the 
guidance in the study terms of reference?). 
VII.b; Design: The Study is well designed: (Are the MOEs fully 
addressed in the study?). 
VII.c; Design: The Study is well designed: (Are the EEAs addressed in 
the study?). 

Presentation of results: Timely, complete, accurate, concise, and 
relevant to the client and stakeholders; 

VIII; Design: The Study is well designed: Presentation of results 
support findings: 
VIII.a; Design: The Study is well designed: Does the report address the 
objectives?. 
VIII.b; Design: The Study is well designed: Does the report present an 
assessment that is well documented and conclusions that are supported 
by the analyses?. 
VIII.c; Design: The Study is well designed: Are conclusions sound and 
complete?. 
VIII.d; Design: The Study is well designed: Are recommendations 
supported by analyses?. 
VIII.e; Design: The Study is well designed: Is a realistic range of 
options provided?. 
VIII.f; Design: The Study is well designed: Are the study results 
presented in the report in a clear manner?. 
VIII.g; Design: The Study is well designed: Are study participants/ 
stakeholders (i.e., services and Combatant Commands) informed of the 
study results and recommendations?. 

Source: GAO analysis of industry and DOD study and research standards. 

[End of table] 

We used these relevant standards as our criteria to assess the reported 
MCS results. All eight key areas of the study process were considered 
to have equal importance relative to the soundness and completeness of 
the study; that is, a sufficiently serious concern in any category 
could raise questions concerning the adequacy and completeness of the 
report. The analysts independently reviewed evidence relevant to each 
subquestion, including the study itself, the study Terms of Reference, 
and its strategic planning guidance. For each of the subquestions in 
the key study process areas, the analysts determined whether (1) the 
evidence had no limitations or raised no concerns, (2) the evidence had 
some limitations or raised some concerns, (3) the evidence had 
significant limitations or raised significant concerns, or (4) we could 
not determine the extent of limitations or concerns because there was 
not sufficient information. The analysts then met, compared, and 
discussed their individual assessments, and reached an overall 
assessment for each subquestion. Areas of the study where we identified 
either "some" or "significant" limitations or concerns were considered 
to affect the adequacy or completeness of the study. Additionally, 
areas of the study that could not be assessed because of the lack of 
supporting documentation were considered to affect the credibility of 
the study. 

Throughout our review PA&E officials told us that the documentation 
needed to support and verify the key analytical and decision-making 
processes used to conduct the MCS, documentation that was vetted and 
approved by DOD leadership and all of the study participants, would not 
be completed and available for our review until the study report was 
issued. However, after the report was issued, we were told that the 
report provides all of the supporting documentation needed and that the 
other documentation we requested could not be provided. As a result, we 
were unable to determine the adequacy and completeness of the 
analytical and decision-making processes that supported the MCS effort 
to evaluate the credibility of the study. We believe these processes 
are significant to the credibility of the study and its results. 

We conducted our review from July 2004 through July 2006 in accordance 
with generally accepted government auditing standards. 

[End of section] 

Appendix II: Comments from the Department of Defense: 

Deputy Secretary Of Defense: 
1010 Defense Pentagon: 
Washington, DC 20301-1010: 

Aug 30 2006: 

The Honorable David M. Walker: 
Comptroller General of the United States: 
U.S. Government Accountability Office: 
441 G Street, N.W. 
Washington, DC 20548: 

Dear Mr. Walker: 

This is the Department of Defense (DoD) response to the GAO draft 
report, GAO-06-938, "Defense Transportation: Study Limitations Raise 
Questions about the Adequacy and Completeness of the Mobility 
Capabilities Study (MCS) and Report," dated August 21, 2006 (GAO Code 
350558). DoD's responses to the report's recommendations are enclosed. 

The GAO draft report contains misleading information and factual 
errors. The Department stands by the adequacy and completeness of the 
MCS, which is one of the most comprehensive capability studies ever 
conducted by the Department of Defense. The data and models used by the 
study are sound, and the results of the study are valid. Furthermore, 
in its groundbreaking assessment of homeland defense mission needs, the 
MCS accurately reflects the Department's most current understanding of 
this developing national mission. Lastly, MCS insights - drawn from the 
study's broad array of mobility metrics and detailed operational 
simulations - significantly enhanced senior leaders' deliberations 
during the 2005 Quadrennial Defense Review. 

The MCS was a collaborative effort led by the Office of the Secretary 
of Defense and the Joint Staff, and its conclusions are well accepted 
by the civilian and military leadership of the Department. In his March 
2006 Congressional testimony, the Commander, U.S. Transportation 
Command acknowledged the study's finding by stating that the planned 
strategic airlift fleet of 292 aircraft "is about the right capacity." 
Likewise, during a press conference in November 2005, the Vice Chairman 
of the Joint Chiefs of Staff expressed his support for the study, 
citing the MCS finding that the Department has "a very capable and 
adequate airlift fleet." 

Signed: 

Enclosure: 
As stated: 

Unclassifed: 

GAO Draft Report - Dated August 21, 2006 GAO CODE 350558/GAO-06-938: 

"Defense Transportation: Study Limitations Raise Questions about the 
Adequacy and Completeness of the Mobility Capabilities Study and 
Report" 

Department Of Defense Comments To The Recommendations: 

Recommendation 1: The GAO recommended that the Secretary of Defense, 
when conducting future mobility capabilities studies, beginning with 
any study currently underway, develop models and data for all critical 
missions, such as homeland defense, and processes, such as the flexible 
deterrent options/deployment order process. 

DOD Response: DoD concurs. The Department plans to continue its ongoing 
efforts to enhance the models and data collection processes used to 
assess mobility capabilities across the full range of strategic 
missions. The models used in the MCS are sound and have consistently 
produced valid results in the four mobility studies conducted by DoD 
since the end of the Cold War. Furthermore, as recommended in the MCS 
report, DoD supports the notion that continual improvements are needed 
to provide enhanced analytic tools for the Department as it strives to 
address complex real-world processes. 

Recommendation 2: The GAO recommended that the Secretary of Defense, 
when conducting future mobility studies, beginning with any study 
currently underway, include in study reports an explanation of how 
ongoing and follow-on studies and modeling and data limitations that 
are referenced in the report could affect the reported results. 

DOD Response: Dod does not understand this recommendation. While a 
completed study can recommend that follow-on studies be conducted, it 
cannot explain how future studies might affect the results of the 
current study. 

Recommendation 3: The GAO recommended that the Secretary of Defense, 
when conducting future mobility capabilities studies, beginning with 
any study currently underway, incorporate both mobility and warfighting 
metrics in determining capabilities. 

DOD Response: DoD concurs. In fact, the MCS employed a rigorous process 
by which the Services, Combatant Commands, and the Joint Staff 
collaboratively developed warfighting metrics. These metrics were used 
along with a comprehensive set of mobility metrics for airlift, 
sealift, surface transport, and prepositioned equipment to determine 
the adequacy of the full spectrum of mobility capabilities. 

GAO Draft Report --Dated August 21, 2006 GAO CODE 350558/GAO-06-938: 

"Defense Transportation: Study Limitations Raise Questions about the 
Adequacy and Completeness of the Mobility Capabilities Study and 
Report" 

Department Of Defense Technical Comments: 

The following are three examples of factual errors and misleading 
information contained in the draft GAO report: 

1. Page 3: "The [modeled] year of 2012 did not place as much demand for 
mobility assets in support of smaller military operations, such as 
peacekeeping, as other years." 

Response: False. The seven-year demand (2007-2013) developed as part of 
the Baseline Security Posture, and used by the MCS, does not have 
significant variance from year to year. 2012 demand is not 
significantly less than 2009, and is larger than 2013. 

It is important to note the fact that the MCS modeled a surge demand on 
the mobility system in 2012 that far exceeds anything this nation has 
experienced since World War II, In doing so, the study correctly 
applied the Department's strategic planning framework (1-4-2-1) and its 
guidance with respect to the conduct of concurrent lesser contingencies 
during overlapping war fights. GAO has incorrectly focused on the 
number of operations, not the level of effort. 

2. Page 4: "The use of war fighting metrics is a measure to determine 
whether combat tasks, such as achieving air superiority, are achieved. 
However, they do not measure whether appropriate personnel, supplies, 
and equipment arrived in accordance with timelines." 

Response: False. The war fighting metrics developed by the MCS do 
measure whether appropriate personnel, supplies, and equipment arrived 
in accordance with timelines. 

In fact, the MCS employed a rigorous process to develop war fighting 
metrics that were used along with a comprehensive set of mobility 
metrics for airlift, sealift, and surface transport. These metrics were 
used to determine if the modeled war fights accomplished the 
commander's objectives within the right timelines. As we explained to 
GAO, being able to achieve a desired task within the desired timeline 
requires the appropriate personnel, supplies and equipment to be in 
place on time, indicating that the transportation capabilities are 
adequate. 

3_ Page 3: "The MCS also was unable to model the flexible deterrent 
options/deployment order process . . 

Response: False. The MCS DID analyze flexible deterrent option (FDO) 
movements to the theater. As part of the MCS analysis, the study 
modeled the flow of forces in response to rising tensions in various 
regions of the world, Forces were flowed to the region in anticipation 
of operations before war plans were executed. These flexible deterrent 
options were included in the MCS analysis. What the study did not do 
was model the deployment order process used in OIF. Rather, the study 
used the time-phased force deployment data (TPFDD) process as the 
accepted methodology for flowing follow-on forces. 

4. Page 3: "The MCS modeled hypothetical homeland defense missions 
rather than actual homeland defense demands because the specific 
details of the missions were still being determined, and DoD 
acknowledged that the data used may be incomplete." 

Response: The statement is misleading. We are not sure what the report 
means by "actual homeland defense demands." Actual demands are 
encountered in response to actual events. The MCS was intended to 
inform the DoD leadership concerning the impact of potential demand on 
the mobility system, and to assess the risks associated with different 
potential demand levels. The study used the latest approved homeland 
defense scenarios developed by NORTHCOM and PACOM, as well as the 
Department's current planning guidance, to determine the range of 
mobility assets needed to support a range of missions. Given the many 
unknowns associated with homeland defense, the study assessed low, 
moderate, and high levels of DoD support for these missions. 

5. Page 3: "Aspects of modeling and data were inadequate." 

Response: This statement is misleading. These are the same models that 
the Department has relied on to complete three previous mobility 
studies since the end of the Cold War. Furthermore, the Department has 
dedicated significant resources to make sure that these models and the 
data collection processes are adequate. The fact that the study 
recommends future improvements was meant to focus future enhancements 
as the Department strives to address increasingly complex real world 
issues. The MCS models and data were adequate to assess relevant 
aspects of the missions required to support the National Military 
Strategy. 

GAO's Responses to DOD's Technical Comments: 

1. DOD disagreed with our assessment that the modeled year--2012--did 
not place as much demand for mobility assets in support of smaller 
military operations, such as peacekeeping, as other years. DOD also 
stated that we incorrectly focused on the number of operations, not the 
level of effort. We disagree. The MCS report (Annex A to Appendix F) 
made no distinction between the number of lesser contingencies and the 
level of effort. Specifically, the Vignettes for Baseline Security 
Posture Analysis did not report the level of effort by year and instead 
aggregated the data, in many instances across several modeled years. 
Consequently, we compared the number of operations conducted in the 
model year. Throughout our review, PA&E officials consistently told us 
that the completed MCS report would contain all the documentation 
needed to support its analyses. Furthermore, although demand in the 
modeled year may exceed previous efforts, the MCS was chartered to 
assess the ability of the mobility system to support the National 
Military Strategy into the next decade. The size of the selected model 
year in relation to efforts conducted between 1941 and 2006 is not at 
issue. As our report makes clear, our concern is that modeling what 
appears to be the least demanding year does not address whether the 
United States has sufficient capability to support national objectives 
during a peak demand period and may underestimate and underreport 
demands to senior decision makers. 

2. DOD disagreed with our observation that the MCS report does not 
provide a clear understanding of the direct relationship of warfighting 
objectives to transportation capabilities. We disagree. We understand 
that achieving a combat task requires delivering the right commodity to 
the right place at the right time. However, the specific combat tasks 
(e.g., attaining air superiority) necessary to satisfy the commander's 
campaign objectives are not a direct measure of mobility capability. 
For example, the problems in using a single metric are reflected in the 
MCS Appendix H, where the MCS report states that "the study itself 
still had difficulty in evaluating the operational impact of the 
delivery of theater support elements," adding that "we [DOD] were 
unable to develop a satisfactory mechanism to capture the linkage of 
the closely related, but delayed, follow-on support needed." Finally, 
the MCS concludes that "there was no way to model a decrease in [Air 
Force] squadron effectiveness if this support was late. Additional 
effort is required to develop a methodology for evaluation the 
operational impact of support equipment availability." We continue to 
believe, and DOD agreed with our recommendation, that warfighting 
metrics, in conjunction with mobility metrics, can give decision makers 
a full picture of the capabilities needed to meet a specific 
warfighting goal. 

3. DOD disagreed with our statement that the MCS was unable to model 
the flexible deterrent options/deployment order process and that the 
study in fact analyzed flexible deterrent option (FDO) movements to 
theater. We do not dispute that DOD analyzed FDO movements as part of 
the MCS analysis. However, the degree to which the MCS analyses 
successfully modeled FDOs is in question. The MCS report, Appendix H, 
stated that an individual FDO is essentially the same as a deployment 
order. It also states in that section that "Deployment orders [DEPORDS] 
are issued to deploy specific capabilities as commitment decisions are 
made. This was not modeled due to lack of data on how DEPORDS would 
have been issued for an MCO [major combat operation] deployment." In 
the same paragraph, the MCS concludes that "the impact on the mobility 
system of the DEPORD process should be assessed in follow-on MCS 
analyses," adding that "there is a data deficit on how to model and 
execute a DEPORD process." Furthermore, the MCS report states that 
"additional analysis is required to investigate the implications of the 
DEPORD process decisions and provide data for future decision-makers to 
develop a DEPORD execution process." 

4. DOD believes our statement concerning homeland defense missions is 
misleading and is not sure what the report means by "actual homeland 
defense demands." We removed the word "actual" and clarified our report 
to discuss "demands derived from a well defined and approved concept of 
operations for homeland defense", which were not available for the 
study according to the MCS report. Furthermore, in chapter 4, the MCS 
report states that "maintaining a dedicated capability to support 
multiple, nearly simultaneous homeland defense/civil support events 
concurrent with the peak demand period of two overlapping warfights, 
greatly exceeds programmed lift capabilities". This raises questions 
about the conclusions of the MCS that there are adequate mobility 
capabilities to meet national security objectives. Also, in Chapter 3 
of the MCS report, it states that the DOD homeland defense concept of 
operations required refinement and was one of nine issue areas cited 
within the homeland defense portion of the study that "need to be 
addressed and investigated in more detail." All of these nine areas 
potentially impact mobility support for homeland defense operations. 
Moreover, the MCS Executive Summary notes that reassessment of these 
missions is required as DOD's role in homeland defense evolves. The MCS 
report, chapter 4, concludes by calling for further refinement of 
mission requirements, continuing risk assessments, and an effort to 
determine corresponding mobility solutions. We continue to believe that 
the MCS conclusion that adequate mobility capability exists is 
conditional given the results of the homeland defense portion of the 
study and that the accuracy and completeness of the data, modeling, and 
results for this portion of the MCS remain in question. 

5. We disagree with DOD's characterization that our information was 
"misleading" regarding the adequacy of some aspects of the MCS' 
modeling and data. Furthermore, we continue to disagree with DOD's 
statement that the models and data used by the study were sound and 
adequate to assess relevant aspects of missions required to support the 
National Military Strategy, and that the results of the study are 
valid. In this report, as in our September 14, 2005 report,[Footnote 8] 
we reaffirm our concern that the data and models used by the study may 
not be sound and the results may not be valid since the verification, 
validation, and accreditation (VV&A) of the models and data used to 
conduct the study was not done in accordance with DOD policy or 
relevant research standards. VV&A of models and data reduces the risk 
inherent in the use of models and simulations by improving the 
credibility of modeling and simulation results. We do not dispute DOD's 
assertion that it has relied upon the same models to produce mobility 
studies done "since the end of the Cold War". However, as we discuss in 
our report, the MCS report fails to explain or qualify the impact that 
identified data or modeling limitations might have on its results. For 
example, in the MCS chapter 4, entitled Operational Data, the MCS 
states that "data deficiencies negatively affected MCS's ability to use 
current execution data to project future requirements and assess system 
performance." Unclear is the extent to which these deficiencies 
impacted the MCS ability to meet the objective of identifying mobility 
capability gaps, overlaps, or excesses and provide associated risk 
assessments, an MCS objective. Similarly, in the section of chapter 4 
entitled Analysis Tools, the report states that "MCS analysis revealed 
several deficiencies in existing mobility models." The section 
concludes with five recommended tool enhancements but it does not 
explain the impact that the absence of these enhanced tools may have. 
We continue to believe that because of these modeling and data 
limitations, the MCS may have incorrectly estimated the future mobility 
requirements needed to support homeland defense missions, smaller 
contingencies, and major combat operations. 

[End of section] 

Appendix III: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

William M. Solis, (202) 512-8365 or solisw@gao.gov: 

Acknowledgments: 

Ann Borseth, Assistant Director; Brian Lepore, Assistant Director; 
Nabajyoti Barkakati; Renee Brown; Claudia Dickey; Ron La Due Lake; 
Oscar Mardis; Deborah Owolabi; Kenneth Patton; and Stephen Woods made 
significant contributions to this report. 

FOOTNOTES 

[1] S. Rep. 108-260, at 126 (2004). 

[2] Examples of the documentation we requested to support and verify 
key analytical and decision-making processes used by DOD to conduct the 
MCS included (1) the accreditation report and supporting documentation 
or evidence of the verification, validation, and accreditation process 
for the models and data used in the MCS; (2) copies of MCS working 
group meeting minutes that verify and validate the analytical processes 
the various MCS study teams and study participants used to vet and 
agree upon data, scenarios, assumptions, models, and associated risk; 
and (3) copies of MCS General Officer Steering Committee and Executive 
Committee meeting minutes that verify and validate the analytical and 
decision-making processes the DOD senior leadership used to vet and 
agree upon the key data, scenarios, assumptions, models, and associated 
risk used to conduct the MCS, as well as agreement with the study 
results. 

[3] Deployment orders are issued to deploy specific capabilities as 
commitment decisions are made, rather than a deploying unit's full set 
of equipment or capabilities. Flexible Deterrent Options (FDOs) provide 
escalation options during the initial stages of a conflict. FDOs are 
employed under certain conditions to deter adversarial actions contrary 
to U.S. interests. 

[4] The 2004 National Military Strategy of the United States calls for 
a force sized to defend the homeland, proactively dissuade adversaries 
in and from four global regions, and conduct two overlapping "swift 
defeat" campaigns. Even when committed to a limited number of lesser 
contingencies, the force must be able to "win decisively" in one of the 
two campaigns. This "1-4-2-1" force-sizing construct places a premium 
on increasingly innovative and efficient methods to achieve objectives. 

[5] In joint military planning, time-phased force deployment data are 
defined as a computer database that contains detailed personnel and 
cargo planning data; it usually includes priority and sequencing of 
deploying forces. 

[6] The baseline security posture projects the position from which 
combatant commanders will perform future missions, including how they 
will address the global war on terrorism, ongoing operations, and other 
day-to-day activities to which U.S. forces remain committed and from 
which they are not likely to disengage entirely. 

[7] See GAO, Defense Transportation: Opportunities Exist to Enhance the 
Credibility of the Current and Future Mobility Capabilities Studies, 
GAO-05-659R (Washington, D.C.: Sept. 14, 2005), for a more detailed 
discussion. 

[8] See GAO, Defense Transportation: Opportunities Exist to Enhance the 
Credibility of the Current and Future Mobility Capabilities Studies, 
GAO-05-659R (Washington, D.C., September 14, 2005), for a more detailed 
discussion. 

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