Navy Readiness: Actions Needed to Address Costly Maintenance Delays Facing the Attack Submarine Fleet
Released: 2018-11-19T00:00:00


Highlights: section_title: Why GAO Did This Study
paragraphs: According to the Navy, its 51 attack submarines provide the United States an asymmetric advantage to gather intelligence undetected, attack enemy targets, and insert special forces, among others. These capabilities make attack submarines some of the most–requested assets by the global combatant commanders.

GAO was asked to review the readiness of the Navy's attack submarine force. This report discusses the extent to which the Navy (1) has experienced maintenance delays in its attack submarine fleet and costs associated with any delays; and (2) has addressed any challenges and developed mitigation plans for any maintenance delays. GAO analyzed readiness information from fiscal years 2008-2018, operating and support costs, maintenance performance, and other data; visited attack submarines and squadrons; and interviewed public and private shipyard and fleet officials.

This is a public version of a classified report issued in October 2018. Information the Department of Defense deemed classified or sensitive, such as attack submarine force structure requirements and detailed data on attack submarine maintenance delays, has been omitted.

section_title: What GAO Found
paragraphs: The Navy has been unable to begin or complete the vast majority of its attack submarine maintenance periods on time resulting in significant maintenance delays and operating and support cost expenditures. GAO's analysis of Navy maintenance data shows that between fiscal year 2008 and 2018, attack submarines have incurred 10,363 days of idle time and maintenance delays as a result of delays in getting into and out of the shipyards. For example, the Navy originally scheduled the USS Boise to enter a shipyard for an extended maintenance period in 2013 but, due to heavy shipyard workload, the Navy delayed the start of the maintenance period. In June 2016, the USS Boise could no longer conduct normal operations and the boat has remained idle, pierside for over two years since then waiting to enter a shipyard (see figure). GAO estimated that since fiscal year 2008 the Navy has spent more than $1.5 billion in fiscal year 2018 constant dollars to support attack submarines that provide no operational capability—those sitting idle while waiting to enter the shipyards, and those delayed in completing their maintenance at the shipyards.

The Navy has started to address challenges related to workforce shortages and facilities needs at the public shipyards. However, it has not effectively allocated maintenance periods among public shipyards and private shipyards that may also be available to help minimize attack submarine idle time. GAO's analysis found that while the public shipyards have operated above capacity for the past several years, attack submarine maintenance delays are getting longer and idle time is increasing. The Navy may have options to mitigate this idle time and maintenance delays by leveraging private shipyard capacity for repair work. But the Navy has not completed a comprehensive business case analysis as recommended by Department of Defense guidelines to inform maintenance workload allocation across public and private shipyards. Navy leadership has acknowledged that they need to be more proactive in leveraging potential private shipyard repair capacity. Without addressing this challenge, the Navy risks continued expenditure of operating and support funding to crew, maintain, and support attack submarines that provide no operational capability because they are delayed in getting into and out of maintenance.

section_title: What GAO Recommends
paragraphs: GAO recommends that the Navy conduct a business case analysis to inform maintenance workload allocation across public and private shipyards. The Department of Defense concurred with GAO's recommendation.

section_title: Letter
paragraphs: The Navy spends over $9 billion annually to operate and sustain its fleet  of 51 attack submarines—consisting of 33 Los Angeles class, 3 Seawolf  class, and 15 Virginia class submarines—that vary in age, size, and  capability. These submarines are responsible for attacking enemy surface  ships and submarines, intelligence collection and surveillance, striking  land targets, and special operations force insertion. According to Navy  documentation, attack submarines’ stealthy nature provides an  asymmetric advantage for gathering intelligence undetected and, due to  their nuclear power, allows for prolonged underwater operations with few  practical limits. These capabilities make attack submarines some of the  most–requested assets by the geographic combatant commanders.

Providing the military forces needed to deter war and to protect the  security of the United States is a fundamental mission of the Department  of Defense (DOD), and DOD has made the sustainment of ready forces a  priority for meeting mission needs. Each of the military services is  generally smaller and less combat-ready today than it has been in many  years. We reported in May 2016 that the Navy faced significant  challenges in rebuilding readiness, with maintenance delays limiting the  ability of Navy forces to surge to respond to unforeseen crises or           contingencies. In August 2018, we reported that as the military services  take steps to rebuild the readiness of their forces, they continue to be  challenged by a demand for forces that, at times, outpaces the available  supply. DOD has recognized the challenges associated with low  readiness and has made rebuilding the readiness of the military forces a  priority.

You asked us to complete a review of the readiness of the Navy’s attack  submarine force. This report is a public version of a classified report that  we issued on October 31, 2018. This report discusses the extent to which  the Navy (1) has experienced maintenance delays in its attack submarine  fleet and costs associated with any delays; and (2) has addressed any  challenges and developed mitigation plans for any maintenance delays.  The classified report included an objective discussing attack submarine  readiness goals and wartime requirements. DOD deemed this information  to be classified, which must be protected from loss, compromise, or  inadvertent disclosure. Consequently, this public version excludes that  information.

Further, this public report omits certain information that DOD deemed to  be sensitive related to (1) attack submarine force structure requirements,  (2) detailed data on attack submarine maintenance delays, (3) attack  submarine cannibalization rates, (4) maintenance prioritization at the  Navy’s public shipyards, (5) maintenance duration forecasting, and (6)  additional recommendations we made to address these issues. Although  the information provided in this report is more limited, it uses the same  methodology as the classified report.

For our first objective, we reviewed data from Naval Sea Systems  Command on maintenance schedule performance for all attack  submarine depot-level maintenance periods for fiscal years 2008—2018  and any idle periods (that is, time awaiting maintenance and unable to  conduct normal operations) during that time period. We determined  maintenance delays by identifying the elapsed time between the expected  completion date and the actual completion date; and we determined idle  periods by identifying the length of time during which a submarine  awaiting maintenance was unable to conduct normal operations. We also  determined the total amount of time for which a submarine was  unavailable due to actual maintenance and idle time. To estimate costs  associated with maintenance delays and idle time, we calculated average  daily cost factors using data from the Navy’s Visibility and Management of  Operating and Support Costs system. We also interviewed Navy fleet and  squadron officials, submarine crews, and shipyard officials to understand  factors affecting operational availability.

For our second objective, we reviewed the Navy’s plans to mitigate any  maintenance delay challenges and interviewed Navy headquarters, fleet,  and squadron officials, as well as public and private shipyard officials, to  discuss these plans. We visited the three public shipyards—Portsmouth  Naval Shipyard, Norfolk Naval Shipyard, and Pearl Harbor Naval  Shipyard and Intermediate Maintenance Facility—that perform the  majority of attack submarine maintenance; the two private shipyards that  conduct attack submarine maintenance; and Navy facilities in  Connecticut, Virginia, Hawaii, and Guam. We evaluated the Navy’s plans  to address any challenges against criteria in federal standards for internal  control, the Department of Defense’s business case analysis guidebook,  A Guide to the Project Management Body of Knowledge, and guidance in  the Secretary of the Navy’s December 2017 Strategic Readiness Review  on assessing risks to fleet readiness.

To assess the reliability of the data sources used in conducting our  analysis, we reviewed systems documentation and interviewed officials to  understand system operating procedures, organizational roles and  responsibilities, and error-checking mechanisms. We selected the time  frames for each of the data series above after assessing their availability  and reliability to maximize the amount of data available for us to make  meaningful comparisons. We assessed the reliability of each of the data  sources based on Navy documentation and interviews with Navy officials.  We also conducted our own error checks to identify potentially inaccurate  or questionable data, and we discussed with officials any data  irregularities we found. We determined that the data series were  sufficiently reliable for the purposes of summarizing attack submarine  readiness trends and related information. Our scope and methodology  are discussed in greater detail in appendix I.

The performance audit upon which this report is based was conducted  from August 2017 to October 2018 in accordance with generally accepted  government auditing standards. Those standards require that we plan  and perform the audit to obtain sufficient, appropriate evidence to provide  a reasonable basis for our findings and conclusions based on our audit  objectives. We believe that the evidence obtained provides a reasonable  basis for our findings and conclusions based on our audit objectives. We  worked with DOD to prepare this unclassified version of the report for  public release. This public version was also prepared in accordance with  these standards.
subsections: section_title: Background
paragraphs: The Navy currently has 51 attack submarines—comprising 33 Los  Angeles class, 3 Seawolf class, and 15 Virginia class submarines (see  fig. 1). Attack submarines are homeported at bases in the United States:  in New London, Connecticut; Pearl Harbor, Hawaii; Norfolk, Virginia; San  Diego, California; and Bangor, Washington; 4 are homeported overseas,  in the U.S. territory of Guam.

Submarine Safety Controls and Culture  On April 10, 1963, the USS Thresher (SSN  593) sank during deep submergence tests off  the coast of New England. One hundred and  twelve officers and enlisted sailors and 17  civilians perished in the tragedy. The accident  investigation concluded that the Navy did not  have adequate procedures in place to prevent  and respond to a catastrophic flooding  incident. time, and that maintenance delays reduce the amount of time during  which ships and submarines are available for training and operations.

Submarine fleet and squadron officials emphasized the strict safety  culture that permeates the submarine community. This emphasis on  meeting safety certification criteria means that the Navy operates a  supply-based submarine force that does not compromise on adherence to  training and maintenance standards to meet combatant commander  demands, according to these officials (see sidebar). Officials added that  the Navy will delay deployment dates if necessary to ensure that these  standards are met. As a result, deployed readiness is high and attack  submarines are in excellent materiel condition as compared with the rest  of the Navy fleet.

The loss of the USS Thresher and its crew  spurred the Navy to establish stringent safety  requirements for submarines to prevent  another loss at sea. Following the accident,  the Navy established submarine safety  certification criteria to provide maximum  reasonable assurance that critical systems  would protect the crew from flooding and  allow the submarine to conduct an emergency  surfacing should flooding occur. This  program, known as SUBSAFE, is still in use  today, to ensure that these critical systems  receive a high quality of work and that all  work is properly documented. According to  the Navy, the SUBSAFE certification status of  a submarine is fundamental to its mission  capability, as it provides a thorough and  systematic approach to quality, and to a  culture that permeates the entire submarine  community. According to Navy officials, since  the SUBSAFE program was established in  1963, no SUBSAFE-certified submarine has  ever been lost.

The Navy has been unable to begin or complete the vast majority of its  attack submarine maintenance periods on time resulting in significant  maintenance delays and operating and support cost expenditures. Our  analysis of Navy maintenance data shows that between fiscal year 2008  and the end of fiscal year 2018, attack submarines will have incurred  10,363 days of idle time and maintenance delays as a result of delays in  getting into and out of the shipyards.

Our analysis found that the primary driver affecting attack submarines are  delays in completing depot maintenance. For example, of the 10,363 total  days of lost time since fiscal year 2008, 8,472 (82 percent) were due to  depot maintenance delays. As we previously reported, completing ship  and submarine maintenance on time is essential to Navy readiness, as  maintenance periods lasting longer than planned could reduce the  number of days during which ships and crews are available for training or  operations.

Attack submarines also face delays in beginning maintenance when the  public shipyards have no available capacity, in some cases forcing  submarines to idle pierside because they are no longer certified to  conduct normal operations. According to Navy officials, the SUBSAFE  program—its program to ensure and certify submarine safety—requires  submarines to adhere to strict maintenance schedules and pass materiel  condition assessments before they are allowed to submerge. Attack  submarines that go too long without receiving required maintenance are  at risk of having their materiel certification expire. Should this certification  expire, these submarines are restricted to sitting idle, pierside, while they  wait until a shipyard has the capacity to begin their maintenance period  (see fig. 2).

We found that since fiscal year 2008, 14 attack submarines have spent a  combined 61 months (1,891 days) idling while waiting to enter shipyards  for maintenance. Idle time incurred while waiting to begin a maintenance  period is often coupled with maintenance delays while at the shipyards,  thus compounding total delays.

We also found that the Navy incurs significant costs in operating and  supporting submarines that are experiencing maintenance delays and idle  time. We analyzed the operating and support costs the Navy incurs on  average to estimate the costs of crewing, maintaining, and supporting  attack submarines that are delayed in getting into and out of the  shipyards. Using historical daily cost data the Navy adjusted for inflation,  we estimated that since fiscal year 2008 the Navy has spent more than  $1.5 billion in fiscal year 2018 constant dollars on attack submarines  sitting idle while waiting to enter the shipyards, and on those delayed in  completing their maintenance at the shipyards (see table 1). While the  Navy would incur these costs regardless of whether the submarine was  delayed, idled, or deployed, our estimate of $1.5 billion represents costs  incurred from fiscal year 2008 through fiscal year 2018 for attack  submarines without receiving any operational capability in return. While  acknowledging the magnitude of these costs, Navy officials stated that  there may be some benefits that could be realized from these operating  and support costs since crews on idle attack submarines can conduct  some limited training.

Operating and support costs include payment of crew salaries,  purchasing of spare parts, and conducting of maintenance, among other  things, but they do not represent the full operational impact incurred by  the Navy from the idle time and maintenance delays. For example, attack  submarine depot-level maintenance requires the use of a drydock, and  officials from the three public shipyards we visited told us that their  drydock capacity was limited. A delayed attack submarine maintenance  period can restrict the use of a drydock for much longer than originally  anticipated, thereby preventing the shipyard from using that drydock to  maintain other vessels, including other types of ships, or to conduct  necessary repairs on the facilities.

section_title: Navy Has Begun to Address Some Challenges Associated with Attack Submarine Maintenance Delays but Has Not Effectively Allocated Maintenance Periods to Limit Idle Time
subsections: section_title: Navy Is Addressing Some Challenges at the Public Shipyards
paragraphs: The Navy has started to address workforce shortages and facilities needs  at the public shipyards. These efforts to address the Navy’s maintenance  challenges are important steps, but they will require several years of  sustained management attention to reach fruition. As we reported in  September 2017, maintenance on ships and submarines may be delayed  for numerous reasons, including workforce gaps and inexperience, the  poor condition of facilities and equipment, parts shortages, changes in  planned maintenance work, and weather. According to Navy officials, all  of these issues continue to affect the Navy’s ability to complete attack  submarine maintenance on time. According to officials, the Navy has  begun to address some of these challenges. For example:

The public shipyards have been hiring to address workforce  shortages. The number of civilian full-time employees at the  shipyards increased from 25,087 in 2007 to 34,160 in 2017, with a  goal to reach 36,100 by 2020. Navy officials cautioned that this newly  hired workforce is largely inexperienced and will require time to attain  full proficiency.

The Navy has released a plan to guide public shipyard capital  investments. In September 2017 we reported that the Navy projected  an inability to support 50 planned submarine maintenance periods  over the ensuing 23 years, due to capacity and capability shortfalls at  the public shipyards. We recommended that the Navy develop a  comprehensive plan for shipyard capital investment. In February  2018 the Navy published its shipyard optimization plan, outlining an  estimated $21 billion investment needed to address shipyard facility  and equipment needs over 20 years to meet the operational needs of  the current Navy fleet, but not the larger fleet size planned for the  future.

section_title: Navy Has Not Effectively Allocated Maintenance Periods among the Public and Private Shipyards to Limit Attack Submarine Idle Time
paragraphs: While the public shipyards have operated above capacity for the past  several years, attack submarine maintenance delays are getting longer  and idle time is increasing. The Navy expects the maintenance backlogs  at the public shipyards to continue. We estimate that, as a result of these  backlogs, the Navy will incur approximately $266 million in operating and  support costs in fiscal year 2018 constant dollars for idle submarines from  fiscal year 2018 through fiscal year 2023, as well as additional depot  maintenance delays.

The Navy may have options to mitigate idle time and maintenance delays.  For example, officials at the private shipyards—General Dynamics  Electric Boat and Huntington Ingalls Industries-Newport News  Shipbuilding—told us that they will have available capacity for repair work  for at least the next 5 years. Although the Navy has shifted about 8  million man-hours in attack submarine maintenance to private shipyards  over the past 5 years, it has done so sporadically, having decided to do  so in some cases only after experiencing lengthy periods of idle time.  According to private shipyard officials, the sporadic shifts in workload  have resulted in repair workload gaps that have disrupted private  shipyard workforce, performance, and capital investment—creating costs  that are ultimately borne in part by the Navy.

We believe that the Navy has not fully mitigated this challenge because it  has not completed a comprehensive business case analysis to inform  maintenance workload allocation across public and private shipyards, and  to proactively minimize attack submarine idle time and maintenance  delays. Such an analysis would help the Navy better assess private  shipyard capacity to perform attack submarine maintenance and would  help it incorporate a complete accounting of all costs, benefits, and risks,  including:  the large operating and support costs of having attack submarines  sitting idle;  the qualitative benefits associated with providing additional availability  to the combatant commanders; and  the potential for additional work at private shipyards to reduce  schedule risk to submarine construction programs by allowing the  yards to build and maintain a stable shipyard workforce.

The April 2011 DOD Product Support Business Case Analysis Guidebook  provides standards for DOD’s process for conducting analyses of costs,  benefits, and risks. It states that data sources used to conduct a  business case analysis should be comprehensive and should include  both quantitative and qualitative values. It notes that benefits, such as the  availability of a weapon system, may be qualitative in nature, and that  DOD should evaluate all possible support options, to include government-  and contractor-provided maintenance. Navy leadership has  acknowledged that they need to be more proactive in leveraging private  shipyard repair capacity, but officials cautioned that maintenance could  cost more at a private shipyard than at a public shipyard. However,  without a complete accounting of all costs, benefits, and risks, the Navy  will remain unable to determine whether the cost of performing a  maintenance period at a private shipyard would outweigh the mission  benefits of having reduced idle time, additional operational availability,  and the potential for reduced risk to submarine construction programs.

section_title: Conclusions
paragraphs: The nation’s investment in attack submarines provides the United States  an asymmetric advantage to gather intelligence undetected, attack enemy  targets, and insert special forces, among other capabilities. However, the  Navy’s attack submarine fleet has suffered from persistent and costly  maintenance delays. Although the Navy has several activities underway  to reduce maintenance delays for the attack submarine fleet, it has not  yet taken additional steps to maximize attack submarine readiness that  fully address challenges such as the allocation of maintenance periods  between public and private shipyards. Without addressing this challenge,  the Navy will not achieve the full benefit of the nation’s investment in its  attack submarines, and it risks continued expenditure of operating and  support funding to crew, maintain, and support attack submarines that  provide no operational capability because they are delayed in getting into  and out of maintenance.

section_title: Recommendation for Executive Action
paragraphs: The Secretary of the Navy should ensure that the Chief of Naval  Operations conducts a business case analysis to inform maintenance  workload allocation across public and private shipyards; this analysis  should include an assessment of private shipyard capacity to perform  attack submarine maintenance, and should incorporate a complete  accounting of both (a) the costs and risks associated with attack  submarines sitting idle, and (b) the qualitative benefits associated with  having the potential to both mitigate risk in new submarine construction  and provide additional availability to the combatant commanders.

section_title: Agency Comments
paragraphs: We provided a draft of the classified version of the report to DOD for  review and comment. That draft contained the same recommendation as  this unclassified version as well as three additional recommendations  DOD deemed sensitive. In written comments provided by DOD (reprinted  in appendix II), DOD concurred with our recommendation stating that it  has taken the first steps to take a more holistic view of submarine  maintenance requirements and impacts across both the public and  private shipyards.

The Navy also provided technical comments, which we incorporated as  appropriate.

We are sending copies of this report to congressional committees; the  Secretary of Defense; the Secretary of the Navy, 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 IV.

section_title: Appendix I: Scope and Methodology
paragraphs: To assess the extent to which the Navy has experienced maintenance  delays in its attack submarine fleet, we analyzed attack submarine  maintenance delay and idle time data from Naval Sea Systems  Command, and we reviewed prior GAO work on shipyard maintenance  delays. The Navy determines depot maintenance delays by counting  each day in which a submarine maintenance period extends beyond the  planned completion date. Two Navy offices within Naval Sea Systems  Command—that is, the Logistics, Maintenance, and Industrial Operations  office and Program Executive Office Submarines—track days incurred  from depot-level maintenance delays and idle time. To determine the total  number of days of maintenance delays for each fiscal year within our  scope, we subtracted the planned completion date from the actual  completion date to produce the number of days of maintenance delays for  each maintenance period for each submarine. We added together the  days of maintenance delays across all attack submarines for each fiscal  year, and then added the fiscal year totals to produce the overall total.  Although the data included some maintenance periods that began before  fiscal year 2008, we counted days of maintenance delays only from  periods that were incurred in fiscal years 2008 through 2018. We also  tracked the total number of days that the Navy completed maintenance  periods ahead of schedule—that is, 153—but we noted these separately  instead of subtracting them from the total number of days of maintenance  delays.

To estimate costs associated with these delays, we analyzed annual data  from fiscal years 2011 through 2017 (the most current data available at  the time of our review) from the Navy’s Visibility and Management of  Operating and Support Costs system. We also reviewed prior work on  determining the operating and support costs of Navy ships. The Navy  calculates total operating and support expenditures for each attack  submarine on an annual basis, as well as the yearly average expenditure  for each attack submarine class, including Los Angeles class, Seawolf  class, and Virginia class blocks one and two. For each class, we  converted the Navy’s annual class averages into daily average costs by  adding the annual class averages together for each year that data were  available, fiscal years 2011 through 2017, then dividing that number by  the total number of days. We then multiplied the daily class average by  the total number of days of maintenance delays and idle time incurred by  submarines within that class, according to our calculations outlined  above, between fiscal year 2008 and fiscal year 2018, and we added  these totals together to produce the total estimated operating and support  cost for days of maintenance delays and idle time incurred during this  period. The data did not include annual class average costs for fiscal  years 2008, 2009, 2010, or 2018. However, the annual class averages for  fiscal years 2011 through 2017 did not show significant variation, so we  applied these averages to 2008, 2009, 2010, and 2018.

To assess the extent to which the Navy has addressed any challenges  and developed mitigation plans for any maintenance delays, we reviewed  the Navy’s plans to address attack submarine maintenance delays and  interviewed Navy headquarters, fleet, and squadron officials, attack  submarine crews, and public and private shipyard officials to understand  any plans to address attack submarine maintenance delays and idle time.  We analyzed data on factors contributing to attack submarine  maintenance delays, such as cannibalization rates. We visited three of  the four public shipyards, including Pearl Harbor Naval Shipyard and  Intermediate Maintenance Facility, Portsmouth Naval Shipyard, and  Norfolk Naval Shipyard, to observe operations, training, and the condition  of the facilities and equipment, and to interview officials about challenges  affecting operational efficiency and performance. We also met with Navy  maintainers at Naval Station Norfolk and Naval Submarine Base New  London, and with the crew of the submarine tenders USS Frank Cable  (AS-40) and USS Emory S. Land (AS-39) in Guam. We toured the two  private shipyards that conduct attack submarine repair work—General  Dynamics Electric Boat and Huntington Ingalls Industries-Newport News  Shipbuilding—and interviewed executives at both locations. We also  toured attack submarines and met with crew leadership, selected  according to which submarines and crews were available for tours at  each of the sites we visited. We visited the USS Boise (SSN 764) at  Naval Station Norfolk and four attack submarines in depot-level  maintenance: the USS Albany (SSN 753), the USS Jefferson City (SSN  759), the USS New Mexico (SSN 779), and the USS Springfield (SSN  761). We met with the crews of two attack submarines assigned to the  operating forces at the time of our visit, the USS Missouri (SSN 780) and  the USS North Dakota (SSN 784). We evaluated the Navy’s plans to  address any challenges against criteria in federal standards for internal  control, which state that agencies should evaluate performance in  achieving key objectives and addressing risks; the Department of  Defense’s business case analysis guidebook, which provides standards  for the process used to conduct analyses of costs, benefits, and risks; the  Project Management Book of Knowledge, which provides best practices  for project management; and the Secretary of the Navy’s December 2017  Strategic Readiness Review, which calls for the early identification of  systemic risks before problems occur.

To assess the reliability of the data sources for conducting analyses to  address all of the objectives in this report, we reviewed systems  documentation and interviewed officials to understand system operating  procedures, organizational roles and responsibilities, and error-checking  mechanisms. We selected the time frames for each of the data series  above after assessing their availability and reliability, to maximize the  amount of data available for us to make meaningful comparisons. We  assessed the reliability of each of the data sources. The Navy provided  information based on our questions regarding data reliability, including  information on an overview of the data, data-collection processes and  procedures, data quality controls, and overall perceptions of data quality.  The Navy provided documentation of how the systems are structured and  what written procedures are in place to help ensure that the appropriate  information is collected and properly categorized. Additionally, we  interviewed Navy officials to obtain further clarification on data reliability,  discuss how the data were collected and reported, and explain how we  planned to use the data. We also conducted our own error checks to look  for inaccurate or questionable data, and we discussed with officials any  data irregularities we found. We conducted these assessments on the  following data for attack submarines: Navy deployed and surge-ready  submarines from fiscal years 2011 through 2018; maintenance timeliness  from fiscal years 2000 through 2018; idle time from fiscal years 2008  through 2018; operating and support costs from fiscal years 2011 through  2017; and cannibalization rates from 2012 through 2017. Some of these  data were used in prior reports, and their reliability had previously been  assessed. After further assessing any data that we had not recently used,  we determined that they were sufficiently reliable for the purposes of  summarizing attack submarine readiness trends and related information.

We interviewed officials, and where appropriate obtained documentation,  at the following locations:

Office of the Chief of Naval Operations

Undersea Warfare Division (N97)

Warfare Integration Division (N83)

U.S. Fleet Forces Command

Commander, Submarine Force, U.S. Atlantic Fleet

Commander, Submarine Squadron 4

Commander, Regional Support Group Groton

Commander, Submarine Force, U.S. Pacific Fleet

Commander, Submarine Squadron 1

Commander, Submarine Squadron 7

Commander, Submarine Squadron 15

Naval Sea Systems Command (NAVSEA)

Logistics, Maintenance, and Industrial Operations (NAVSEA 04)

Program Executive Office, Submarines

Attack Submarine Program Office (PMS 392)

Submarine Maintenance Engineering, Planning, and Procurement  (SUBMEPP)

Supervisor of Shipbuilding, Conversion, and Repair (SUPSHIP)

Newport News, Virginia

Navy Education and Training Command

Submarine Learning Facility Norfolk

Navy Board of Inspection and Survey

Norfolk Naval Shipyard, Norfolk, Virginia

Pearl Harbor Naval Shipyard and Intermediate Maintenance  Facility, Pearl Harbor, Hawaii

Portsmouth Naval Shipyard, Kittery, Maine

Newport News Shipbuilding, Virginia, operated by Huntington  Ingalls Industries

Electric Boat, Groton, Connecticut, operated by General Dynamics  The performance audit upon which this report is based was conducted  from August 2017 to October 2018 in accordance with generally accepted  government auditing standards. Those standards require that we plan  and perform the audit to obtain sufficient, appropriate evidence to provide  a reasonable basis for our findings and conclusions based on our audit  objectives. We believe that the evidence obtained provides a reasonable  basis for our findings and conclusions based on our audit objectives. We  worked with DOD to prepare this unclassified version of the report for  public release. This public version was also prepared in accordance with  these standards.

section_title: Appendix II: Comments from the Department of Defense

section_title: Appendix III: Related GAO Products
paragraphs: Report numbers with a C or RC suffix are Classified. Classified reports  are available to personnel with the proper clearances and need to know,  upon request.

Columbia Class Submarine: Immature Technologies Present Risks to  Achieving Cost Schedule and Performance Goals. GAO-18-158.  Washington, D.C.: Dec. 21, 2017.

Navy Readiness: Actions Needed to Address Persistent Maintenance,  Training, and Other Challenges Affecting the Fleet. GAO-17-809T.  Washington, D.C.: Sept. 19, 2017.

Naval Shipyards: Actions Needed to Improve Poor Conditions that Affect  Operations. GAO-17-548. Washington, D.C.: Sept. 12, 2017.

Navy Readiness: Actions Needed to Address Persistent Maintenance,  Training, and Other Challenges Facing the Fleet. GAO-17-798T.  Washington, D.C.: Sept. 7, 2017.

Military Readiness: DOD’s Readiness Rebuilding Efforts May Be at Risk  without a Comprehensive Plan. GAO-16-841. Washington, D.C.: Sept. 7,  2016.

Navy and Marine Corps: Services Face Challenges to Rebuilding  Readiness. GAO-16-481RC. Washington, D.C.: May 25, 2016.  (SECRET//NOFORN)

Military Readiness: Progress and Challenges in Implementing the Navy’s  Optimized Fleet Response Plan. GAO-16-466R. Washington, D.C.: May  2, 2016.

Navy Force Structure: Sustainable Plan and Comprehensive Assessment  Needed to Mitigate Long-Term Risks to Ships Assigned to Overseas  Homeports. GAO-15-329. Washington, D.C.: May 29, 2015.

section_title: Appendix IV: GAO Contact and Staff Acknowledgments
subsections: section_title: Acknowledgments
paragraphs: In addition to the contact named above, Suzanne Wren, Assistant  Director; Chris Watson, Analyst in Charge; Herb Bowsher; Chris Cronin;  Ally Gonzalez; Cynthia Grant; Carol Petersen; Amber Sinclair; and Cheryl  Weissman made key contributions to this report.

Fast facts: Navy shipyards have been unable to keep up with maintenance demands for attack submarines. As a result, the Navy has spent $1.5 billion since 2008 to support submarines that it could not deploy.

For example, the USS Boise has been docked for over 2 years while waiting for maintenance—with the Navy paying to support it.

The Navy has begun to hire more workers at its shipyards and, in some cases, has shifted more work to private shipyards.

We recommended the Navy assess how to best use public and private shipyards to achieve the full benefit of the nation’s investment in these submarines.

Question-summary annotations: questions: question: What is the current stance of the Navy's submarine maintenance?
answer: The Navy has been unable to begin or complete the vast majority of its attack submarine maintenance periods on time resulting in significant maintenance delays and operating and support cost expenditures. GAO's analysis of Navy maintenance data shows that between fiscal year 2008 and 2018, attack submarines have incurred 10,363 days of idle time and maintenance delays as a result of delays in getting into and out of the shipyards.
child_questions: question: What are examples of these delays?
answer: For example, the Navy originally scheduled the USS Boise to enter a shipyard for an extended maintenance period in 2013 but, due to heavy shipyard workload, the Navy delayed the start of the maintenance period. In June 2016, the USS Boise could no longer conduct normal operations and the boat has remained idle, pierside for over two years since then waiting to enter a shipyard (see figure).

question: What is the cost of such delays?
answer: GAO estimated that since fiscal year 2008 the Navy has spent more than $1.5 billion in fiscal year 2018 constant dollars to support attack submarines that provide no operational capability—those sitting idle while waiting to enter the shipyards, and those delayed in completing their maintenance at the shipyards.

questions: question: What has the Navy done to address the current maintenance challenges?
answer: The Navy has started to address challenges related to workforce shortages and facilities needs at the public shipyards. However, it has not effectively allocated maintenance periods among public shipyards and private shipyards that may also be available to help minimize attack submarine idle time.
child_questions: question: What does the GAO recommend the Navy does to fix the issue?
answer: GAO's analysis found that while the public shipyards have operated above capacity for the past several years, attack submarine maintenance delays are getting longer and idle time is increasing. The Navy may have options to mitigate this idle time and maintenance delays by leveraging private shipyard capacity for repair work.

question: What is preventing the Navy from lowering idle time?
answer: But the Navy has not completed a comprehensive business case analysis as recommended by Department of Defense guidelines to inform maintenance workload allocation across public and private shipyards.
child_questions: question: Have Navy leaders acknowledged this issue?
answer: Navy leadership has acknowledged that they need to be more proactive in leveraging potential private shipyard repair capacity.

question: Why is it necessary for Navy to fix this problem?
answer: Without addressing this challenge, the Navy risks continued expenditure of operating and support funding to crew, maintain, and support attack submarines that provide no operational capability because they are delayed in getting into and out of maintenance.

questions: question: What was the motivation for GAO's report?
answer: GAO was asked to review the readiness of the Navy's attack submarine force.
child_questions: question: What were the main issues discussed in the report?
answer: This report discusses the extent to which the Navy (1) has experienced maintenance delays in its attack submarine fleet and costs associated with any delays; and (2) has addressed any challenges and developed mitigation plans for any maintenance delays.

question: How did the GAO evaluate these issues?
answer: GAO analyzed readiness information from fiscal years 2008-2018, operating and support costs, maintenance performance, and other data; visited attack submarines and squadrons; and interviewed public and private shipyard and fleet officials.