DOD major headquarters activities include the Office of the Secretary of Defense; the Joint Staff; the Offices of the Secretary of the Army and Army Staff; the Office of the Secretary of the Navy and Office of the Chief of Naval Operations; Headquarters, Marine Corps; and the Offices of the Secretary of the Air Force and Air Staff. All personnel working within these headquarters organizations are considered to be performing major headquarters activities functions. Other headquarters organizations identified as major headquarters activities include portions of the defense agencies; DOD field activities; and the combatant commands, along with their subordinate unified commands and respective service component commands. Except for the military service headquarters listed above, DOD refers to these organizations and components that have manpower resources collectively as the Fourth Estate. The DCMO is responsible for ensuring that DOD components are accurately identifying and accounting for major DOD headquarters activities. In addition, department guidance gives the DCMO primary responsibility for improving the efficiency and effectiveness of operations across DOD's business functions and the authority to issue policy and guidance regarding the management and improvement of department business operations. This includes responsibilities related to identifying and monitoring the implementation of cost savings opportunities and efficiencies across DOD's business areas. As part of those responsibilities, the DCMO, as the Chair of the Defense Business Council, can make recommendations to the Deputy's Management Action Group, a senior-level forum that discusses various department-wide management issues. The group works to develop a common management approach to ensure that management actions are coordinated across the defense enterprise. Since 2010, in part in response to the constrained fiscal environment and National Defense Authorization Acts of Fiscal Year 2014 and Fiscal Year 2016, DOD has undertaken efficiency-related efforts to reduce the cost of doing business for major headquarters activities and other administrative and support activities. These include, but are not limited to the following: In May 2010, DOD began an assessment of how the department is staffed, organized, and operated, with the goal of reducing excess overhead costs. In March 2012, DOD conducted the More Disciplined Use of Resources review of bureaucratic structures, business practices, modernization programs, civilian and military personnel levels, and associated overhead costs. In July 2013, the Secretary of Defense set a target for reducing DOD components' total management headquarters budgets by 20 percent for fiscal years 2014 through 2019, including costs for civilian personnel and contracted services, while striving for 20 percent reductions to authorized military and civilian personnel. The National Defense Authorization Act for Fiscal Year 2016 subsequently required the department to achieve additional reductions through fiscal year 2020. In May 2015, DOD concluded its Core Business Process Review. Through this review, the DCMO identified at least $62 billion in potential cumulative savings opportunities across the six business processes--human resources management, healthcare management, financial management, acquisition and procurement, logistics and supply, and real property management--for fiscal years 2016 through 2020. However, in June 2016, we reported that DCMO officials had stated that the potential savings opportunities could not entirely be achieved. Our Cost Estimating and Assessment Guide states that cost estimates are necessary to make decisions and allocate resources and that cost estimates should be reliable--well documented, comprehensive, accurate, and credible--and provide enough information so that someone unfamiliar with a program could easily recreate or update the estimate. The guidance also states that thorough documentation is essential for validating and defending a cost estimate and that the documentation should include enough detail to allow for clear tracking of costs. Doing so will help ensure that cost savings calculated using these estimates are reliable and that agency management and Congress will be able to monitor progress and ensure implementation of these cost savings. DOD has not identified $10 billion in cost savings through fiscal year 2019 as required and does not have a reliable cost savings estimate to support the cost savings it has identified. DOD has identified approximately $13.1 billion in efficiency-related cost savings through fiscal year 2021. However, we determined its cost savings estimate is unreliable because the DOD-provided documentation was not sufficiently detailed to support the estimate. As a result, neither the department nor other decision makers will be able to monitor progress and ensure achievement of the required cost savings. According to documents provided by DCMO officials, DOD has not identified the required $10 billion in efficiency-related cost savings for fiscal years 2015 through 2019. DOD identified $13.1 billion in estimated cost savings for fiscal years 2015 through 2021. DOD considers the specific amount of savings it will achieve by 2019 to be pre- decisional and, therefore, not releasable in a public report. DOD based its cost savings estimate on two separate inputs. The first is associated with headquarters reductions identified and submitted in May 2015 as part of the Section 904 Report. These reductions include reducing the size of DOD headquarters staffs and layers of management, eliminating functions that have little or no added value, and consolidating overlapping and duplicative programs and offices. The second is associated with five categories of DOD-identified efficiency initiatives that were highlighted in DOD's fiscal year 2017 Defense Budget Overview and referenced in DOD's March 2016 update to Congress. The reductions include cost savings related to business operations, service contracts, and information technology. See table 1 for the cost savings estimates that DOD identified in its May 2015 Section 904 Report and March 2016 update to Congress. At the time of our review, officials stated that DOD has not submitted the required report to Congress on its cost savings plan. DCMO officials responsible for submitting the report stated that their intent is to complete and submit a report, but they did not have timeframes for the submission and did not provide a reason for the delay. However, DOD officials acknowledged that the department has not identified the required $10 billion cost savings by fiscal year 2019, and the department does not have specific plans to identify further cost savings within the mandated time period. DCMO officials further stated that other efficiency-related efforts may achieve additional cost savings that they could count toward the requirement, and that the department plans to exceed the requirement by fiscal year 2020. In a June 27, 2017, letter from DOD commenting on a draft of this report, the department stated it identified $938 million in additional savings that it intends to count toward the required cost savings but did not provide a timeframe for achieving these savings or details about them. Moreover, with the additional cost savings, the department acknowledged that it had not yet identified the $10 billion cost savings required but asserted it expected to achieve them by the required date. We determined the cost savings estimate is not reliable because the DOD-provided documentation for the two separate inputs was not sufficiently detailed consistent with the best practices for cost estimates described in our Cost Estimating and Assessment Guide. DCMO officials provided varying levels of documentation related to the two inputs for its cost savings projections. For example, the DCMO provided a March 2016 briefing it gave the Senate Armed Services Committee that included information on both inputs. The briefing described both inputs and briefly described some of the department's plans for achieving the cost savings estimate. However, the briefing did not contain specific information that would convince management and oversight staff that the estimate was credible. Additionally, DOD officials stated that the cost savings through fiscal year 2021 are documented as reductions in the Future Years Defense Program (FYDP). However, the FYDP is the plan that represents DOD's projected funding needs for the department's current budget and for at least the next 4 years, and the plan does not include sufficient detail--such as specific plans to achieve the reductions or specific programs or personnel to be reduced--to allow for the clear identification of the efficiency-related cost savings. DOD-provided documentation for the two inputs was not sufficiently detailed to support reliable estimates, as described below. DCMO based the first part of its estimated cost savings--approximately $5.3 billion--on efficiency-related reductions required by section 904 of the National Defense Authorization Act for Fiscal year 2014 and reported the cost savings in DOD's May 2015 Section 904 Report. DCMO-provided documentation for the estimated cost savings was a summary table listing funding and personnel reductions allocated to various organizations and included a statement that the reductions listed were "not auditable" because the baseline for the reductions had not been established, among other reasons. The documentation did not contain detailed information or specific actions the organizations have taken or planned to take to achieve the cost savings. Without additional details, we cannot determine how DOD calculated or is implementing these reductions. In addition, we previously reported that the department did not have a clear or accurate accounting of the resources that it used as a starting point for reductions; as a result, DOD would be unable to track and reliably report its headquarters reductions and ultimately may not realize significant savings. DOD based the second part of its estimate--which it estimates will save approximately $7.8 billion by fiscal year 2021--on five categories of DOD- identified efficiency-related initiatives that the department identified in its March 2016 update to Congress describing how it would achieve the required cost savings. DOD-provided documentation for the estimated cost savings varied for the five categories. For its Service Requirement Review Boards category, DOD provided documentation showing specific cost savings estimates by organization, an explanation of how those estimates were calculated, and implementation actions that organizations plan to take to achieve the cost savings. In contrast, for the Business Operations Improvements and Defense Resale Optimization categories, DOD's documentation was limited to a summary table without detailed information such as specific actions it will take or an explanation of when such actions will be completed to achieve these cost savings. For the Information Technology Optimization category, DOD-provided documentation was limited to a brief description of the initiatives without specific actions the department plans to take to implement the savings. For the Major Headquarters Activities category, DOD documented the amount of planned cost savings by organization, explained how approximately 25 percent of the cost savings was calculated, and provided an example of how some of the cost savings will be implemented. However, DOD documentation for the remaining Major Headquarters Activities cost savings was limited to a summary of total estimated cost savings by fiscal year without additional information. In addition, DOD officials were unable to explain how the department had calculated the estimated cost savings. For example, for one of the categories, officials provided a description of pilot programs they planned to implement, but they could not provide details about the cost savings they anticipated the programs would achieve. Brief descriptions of the five categories of the DOD-identified efficiency- related initiatives and the supporting documentation the department provided for the estimated cost savings for each category are in table 2. For a more complete description of the five categories, see appendix I. Cost estimates used to make decisions or allocate resources should be reliable--well documented, comprehensive, accurate, and credible--and they should be acceptable to someone unfamiliar with the program. Without detailed documentation regarding how DOD plans to achieve reductions, the department cannot ensure it will achieve cost savings as required by the National Defense Authorization Act for Fiscal Year 2016. DOD has worked to achieve efficiency-related cost savings and reduce its activities related to headquarters, administration, and support. Congress has directed DOD to find headquarters-related efficiencies, including mandating DOD to implement and report on a plan to achieve not less than $10 billion in cost savings from headquarters, administrative, and support activities from fiscal years 2015 through 2019. Although the DCMO has been working on implementing the required plan to save $10 billion, the cost savings estimates underpinning its plans are not reliable because DCMO lacks detailed documentation. As a result, neither DOD nor Congress will be able to monitor progress and ensure the achievement of the required cost savings. As the department seeks to report on and achieve required cost savings, we recommend that the Secretary of Defense direct the Deputy Chief Management Officer to develop reliable cost savings estimates that include detailed information and documentation to allow for clear tracking of cost savings by DOD and Congress. We provided a draft of this report to DOD for review and comment. In written comments on a draft of this report, DOD partially concurred with our recommendation. DOD also provided technical comments, which we incorporated as appropriate. DOD's comments are summarized below and reprinted in appendix II. DOD partially concurred with our recommendation to develop reliable cost savings estimates that include detailed information and documentation to allow for clear tracking of the cost savings by DOD and Congress. DOD noted in its response that the department will continue to manage the efficiency efforts discussed in this report as part of its broader reforms but the department's response did not address how it would implement our recommendation that the department develop reliable, detailed, and well- documented cost savings estimates. In its response, DOD also stated that since receiving our draft report, it had identified $938 million in additional cost savings. We noted the department's identification of these additional savings in our report. We did not, however, modify the totals to reflect these savings because the department did not provide details about how it will achieve these cost savings, such as specific actions it will take or a timeline for completing such actions. In its response, DOD stated that it is tracking cost savings for the Service Requirement Review Boards and Major Headquarters Activity categories--two of the five major categories in our review. For the Service Requirement Review Boards category, we agree and describe in the report DOD documentation that includes reduction targets, risk assessments, timelines, and the specific items to be reduced or eliminated. For the Major Headquarters Activities category, however, DOD-provided support was not sufficiently detailed to allow us to clearly track these savings. As a result, we continue to believe that the Major Headquarters cost savings estimate is unreliable and that DOD will not be able to monitor progress and ensure it achieves the associated savings. DOD acknowledged in its response that it is difficult to track specific cost savings for the other three categories--Information Technology Optimization, Business Operations Improvements, and Defense Resale Optimization. The reason given by the department is that the cost savings are being taken from across multiple organizations, against their top-line budgets. We agree that adjusting programmed budgets for organizations is an important first step in planning for reductions, but we continue to be concerned that without additional details we cannot determine how DOD calculated or is implementing these reductions. DOD stated in its response that some data associated with the savings are pre-decisional and, therefore, not releasable per the Office of Management and Budget guidance set forth in Circulars A-123 and A-11. However, during the course of our work, DOD officials stated that the pre-decisional data were not sufficiently detailed to be used to track cost savings. As a result, we elected not to exercise our right of access to it pursuant to 31 U.S.C. SS 716, which includes a broad right of access to information that is pre- decisional or that represents the deliberative process. Finally, DOD stated in its comments that it is committed to additional reductions and is actively managing efficiencies across the Department and that its reform plan will become part of the Office of Management and Budget's comprehensive plan to reform the Federal Government. DOD stated in its response that it would submit a required report to Congress detailing its reduction plans shortly. Submitting the required report--which was due in February 2016--could help the department explain its plans. To date, however, DOD has not identified the required $10 billion cost savings, and the cost savings estimates underpinning its plans are not reliable because DOD lacks detailed information and documentation about how it is achieving the cost savings. Until DOD addresses our recommendation, we continue to believe that neither DOD nor Congress will be able to monitor progress and ensure the achievement of the required cost savings. We are sending copies of this report to appropriate congressional committees, the Secretary of Defense, the Under Secretary of Defense for Personnel and Readiness, the Deputy Chief Management Officer, the Chairman of the Joint Chiefs of Staff, the Secretaries of the military departments, the heads of the defense agencies and DOD field activities, and other interested parties. In addition, the report is available at no charge on the GAO website at http://www.gao.gov. If you or your staff have any questions about this report, please contact me at (202) 512-3489 or pendletonj@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. In the fiscal year 2017 Department of Defense (DOD) budget request, DOD identified five categories of efficiency initiatives with which it could reduce costs and free up resources needed for readiness and modernization. DOD also referenced the five categories of efficiency initiatives in its March 2016 interim update to Congress regarding the requirement to report on and implement a plan to ensure DOD achieves not less than $10 billion in cost savings from headquarters, administrative, and support activities for fiscal years 2015 through 2019. DOD reported that these categories of efficiency initiatives would contribute to the $10 billion reduction to the department's headquarters, administrative, and support activities required by the National Defense Authorization Act of 2016. According to information reported to Congress in DOD's March 2016 interim update, the five categories of efficiency initiatives will achieve approximately $7.8 billion in cost savings for fiscal years 2017 through 2021. A description of each category is below. The office of the Deputy Chief Management Officer (DCMO) directed the Fourth Estate organizations to identify areas for savings in their service contracts--generally contracts related to a specific task rather than to a specific product--as part of a series of Service Requirement Review Boards. The organizations examined the risk posed to their ability to meet their missions with a 10-percent reduction to service contracts, and then the organizations identified contracts where they could reduce costs. The organizations presented their recommendations for cuts to a Senior Review Panel composed of the DCMO, the Principal Deputy Under Secretary of Defense for Acquisition, Technology, and Logistics and Principal Staff Assistants. DOD officials stated that the Senior Review Panel either approved the proposed cuts or directed alternative reductions. Officials stated that the DCMO was tracking Service Requirement Review Boards cost savings achieved in fiscal year 2017, and that the department was conducting another iteration of reviews in which organizations would be required to review additional service contract funding. DOD documentation related to Service Requirement Review Boards and DOD's associated cost savings estimate includes standardized presentations the organizations presented to the Senior Review Panel. The presentations include reduction targets, risk assessments, timelines, and the specific items to be reduced or eliminated. DOD documentation also includes a summary of DCMO-directed reductions for the organizations for fiscal years 2018 through 2022. DOD previously reported to us that Service Requirement Review Boards would aid in the management and oversight of services' acquisitions. DOD also stated that beginning in fiscal year 2016 the department will use Service Requirement Review Boards to evaluate proposed contract services within the defense agencies and the senior staffs. According to DOD officials, the DCMO and the DOD Chief Information Officer identified six information technology optimization initiatives: 1. Military Integrated Personnel and Pay System--According to DOD officials, this initiative combines the military departments' personnel and pay systems to achieve savings from using fewer resources, simplifying financial reporting, and having more timely and accurate payroll services. Officials stated that the system will leverage commercially available human resource systems. DCMO officials also stated that the system will achieve cost savings beginning in fiscal year 2019 when the current payroll and benefit systems are retired. 2. Defense Travel Modernization-- According to DOD officials, as part of the initiative to reform travel and modernize DOD's travel system, the department is increasing the use of less expensive, non-refundable tickets for select commercial air travel, rather than purchasing the more expensive, fully-refundable tickets. According to DOD officials, in certain markets the cost savings achieved with these less expensive fares more than offset the potential fees incurred when travelers make changes to their itineraries, and as a result they expect to achieve cost savings. DCMO officials stated that facilitating the use of these fares requires changes to DOD travel software and to the Joint Travel Regulations and that DOD will achieve defense travel modernization cost savings beginning in fiscal year 2017. 3. Enterprise Licensing--According to DOD officials, this initiative involves additional monitoring to enable better use of DOD software licenses, which improves business processes. DOD officials told us that they also expect to realize cost savings by purchasing more commercially available software products rather than having software customized. DCMO reported that DOD will achieve enterprise licensing cost savings beginning in fiscal year 2017. 4. Circuit Optimization--According to DOD officials, this initiative involves using fewer and less expensive circuits to accomplish their mission. DCMO reported that DOD will achieve circuit optimization savings beginning in fiscal year 2018. 5. Data Center Infrastructure--According to DOD officials, this initiative involves reviewing data center locations and consolidating centers where services could be combined to save money. 6. National Capital Region Information Technology Consolidation-- According to DOD officials, this initiative involves consolidating the 40 to 50 information technology providers for Pentagon tenants and Fourth Estate organizations in the National Capital Region to decrease duplication and improve the delivery of information technology services. DCMO reported that DOD will achieve National Capital Region information technology consolidation savings beginning in fiscal year 2017. Officials from the office of the DOD Chief Information Officer stated that they were on track to achieve the estimated cost savings and that additional cost savings could be achieved through related information technology commodity management activities, such as the Federal Data Center Consolidation Initiative, if necessary. DOD documentation related to information technology optimization and DOD's associated cost savings estimate is a list of initiatives with a summary of estimated cost savings by fiscal year. Officials stated that the department is tracking implementation of information technology optimization-related cost savings through Resource Management Decisions, but DOD documentation did not allow us to clearly track the savings. According to DOD officials, DOD cost savings related to Major Headquarters Activities involves two types of cost savings--reductions which comprise approximately 75 percent of the savings and those associated with consolidating and reducing the layers of organizational management (i.e., delayering). DCMO-provided documentation did not include specific information about the reductions related to the approximately 75 percent of the cost savings. DOD plans to achieve the other 25 percent of the cost savings by delayering and reducing staff through attrition and reassignments. The DCMO directed delayering for the Office of the Secretary of Defense and Defense Agencies and Field Activities and identified cost savings for fiscal years 2017 through 2021. As part of delayering, organizations used DCMO's guidance, which recommended that there be no more than five organizational layers within the Office of the Secretary of Defense, among other things. DCMO's guidance also recommended that organizations pursue cross-organizational partnerships and shared work activities when possible. Officials stated that DOD recorded the resulting personnel changes in the Fourth Estate Manpower Tracking System. DOD documentation related to overall Major Headquarters Activities reductions, including delayering, and DOD's associated cost savings estimate include a summary of reductions for fiscal years 2017 through 2021. DOD also provided a summary of planned delayering cost savings by organization for fiscal years 2017 through 2020 as well as an example of an implementation plan that describes specific actions to be taken and how those actions would affect the organization's mission. DOD-provided documentation did not identify how DOD plans to achieve the cost savings not related to delayering and was not sufficiently detailed to allow us to clearly track these savings. However, officials stated that they have created more than 200 new Program Elements in the FYDP that they expect will improve tracking of major headquarters-related savings in the future by improving visibility of headquarters resources. DOD officials stated that the department directed reductions to DOD's Fourth Estate organizations through cuts from the military departments. A DCMO official stated that the department achieved cost savings in fiscal year 2017 by reducing the rates that the Defense Finance and Accounting Service charged to the military departments. DOD documentation related to business operations and DOD's associated cost savings estimate is a summary of estimated cost savings by fiscal year. This documentation was not sufficiently detailed to allow us to clearly track the savings. Officials stated that the business operations reductions are documented in Resource Management Decisions. Additional savings from return on investment are tracked as part of the annual review of business systems certification requests through the investment management review process. However, officials stated that they could not attribute business operations cost savings to specific Fourth Estate organizations or Program Elements in the Future Years Defense Program (FYDP). Officials stated that the cuts would be taken and, if necessary, Fourth Estate organizations would repurpose old business operations systems or cut back programs. We found in November 2016 that the Defense Commissary Agency planned to achieve cost savings through pilot programs at the Defense Commissary Agency's commissaries, including different pricing methods. However, this plan did not include statements about assumptions, its methods, or specific time frames related to cost savings. DOD responded to our recommendation to develop a plan to support its efforts by stating that the department chartered the Defense Resale Business Optimization Board in 2016 to develop a plan and approve initiatives for piloting the plan. An official stated that the department would achieve fiscal year 2017 cost savings by returning unobligated funds from the Defense Commissary Agency's working capital fund to the military services, implementing previously-planned store closures, and sourcing locally-produced goods at DOD's commissaries and exchanges. The Defense Commissary Agency began implementing pilot programs related to pricing and providing alternatives to national brands in fiscal year 2017. An official stated that DOD tracks defense resale-related cost savings in the FYDP using "Commissary Retail Sales" Program Elements; however Defense Commissary Agency documentation did not include sufficient detail to allow us to clearly track the cost savings. . In addition to the contact named above, Margaret A. Best (Assistant Director), Michele Fejfar, Alexandra Gonzalez, Jana Hopkins, Mae Jones, Edward Malone, Amanda Manning, Brendan K. Orino, Carol Petersen, and John Van Schaik made major contributions to this report. DOD Commissaries and Exchanges: Plan and Additional Information Needed on Cost Savings and Metrics for DOD Efforts to Achieve Budget Neutrality. GAO-17-38. Washington, D.C.: November 9, 2016. Defense Headquarters: Improved Data Needed to Better Identify Streamlining and Cost Savings Opportunities by Function. GAO-16-286. Washington, D.C.: June 30, 2016. DOD Service Acquisition: Improved Use of Available Data Needed to Better Manage and Forecast Service Contract Requirements. GAO-16-119. Washington, D.C.: February 18, 2016. Defense Headquarters: DOD Needs to Reassess Personnel Requirements for the Office of the Secretary of Defense, Joint Staff, and Military Service Secretariats. GAO-15-10. Washington, D.C.: January 21, 2015. Defense Headquarters: DOD Needs to Reevaluate Its Approach for Managing Resources Devoted to the Functional Combatant Commands. GAO-14-439. Washington, D.C.: June 26, 2014. Defense Headquarters: DOD Needs to Periodically Review and Improve Visibility of Combatant Commands' Resources. GAO-13-293. Washington, D.C.: May 15, 2013. Defense Headquarters: Further Efforts to Examine Resource Needs and Improve Data Could Provide Additional Opportunities for Cost Savings. GAO-12-345. Washington, D.C.: March 21, 2012. Defense Headquarters: Total Personnel and Costs Are Significantly Higher Than Reported to Congress. GAO/NSIAD-98-25. Washington, D.C.: October 30, 1997.

Summary:
Section 346(a) of the National Defense Authorization Act for Fiscal Year 2016 requires that DOD implement a plan to achieve no less than $10 billion in cost savings from headquarters, administrative, and support activities for fiscal years 2015 through 2019. Congress further mandated DOD to report on that plan with its budget submissions for fiscal years 2017 through 2019, and for GAO to examine each report. DOD has not submitted the report that was required with the department's fiscal year 2017 budget submission but did submit a letter to Congress in March 2016 with an interim update on its plan. GAO examined the extent to which DOD has identified the cost savings required through fiscal year 2019 using reliable cost savings estimates. GAO reviewed DOD's interim update and related documentation, including DOD budget and guidance documents. GAO also interviewed DOD officials about the status of the plan and related efficiency efforts. This is a public version of a sensitive report that is being issued concurrently. Information on budget data that DOD deemed sensitive has been redacted from this report. DOD has not identified $10 billion in cost savings through fiscal year 2019 as required and does not have a reliable cost savings estimate to support the cost savings it has identified. According to DOD documents, the department estimates that it will save about $13.1 billion from fiscal years 2015 through 2021. It based its cost savings estimate on savings DOD (1) identified in May 2015 and (2) reported to Congress in its March 2016 interim update (see table below). DOD's projected cost savings estimate is unreliable because DOD-provided documentation, when compared with best practices for cost estimates, was not sufficiently detailed to support the estimate. According to DOD's internal assessment, the $5.3 billion in cost savings identified in the May 2015 report were "not auditable" because the baseline for reductions had not been established, among other reasons. The March 2016 update identified additional cost savings in categories of efficiencies, and the level of detail in DOD's documentation related to these categories varied. For example, for one category, documentation showed cost savings estimates by organization, how estimates were calculated, and actions organizations planned to take to achieve the cost savings. In contrast, for two categories, documentation identified cost savings by fiscal year but did not include information on specific actions planned to achieve them. Without detailed documentation allowing someone unfamiliar with the program to easily recreate or update the cost savings estimate, the estimate is not reliable and, thus, does not allow for clear tracking of cost savings. GAO recommends that DOD develop reliable cost savings estimates that include detailed information and documentation. DOD partially concurred with this recommendation but did not address how it intended to implement the recommendation. GAO continues to believe the recommendation is warranted.