The F-35 Lightning II program is a joint, multinational acquisition intended to develop and field an affordable family of next-generation strike fighter aircraft for the United States Air Force, Navy, Marine Corps, and eight international partners. There will be three variants of the F-35. (1) The conventional takeoff and landing (CTOL) variant, designated the F-35A, will be a multirole, stealthy strike aircraft replacement for the Air Force’s F-16 Falcon and the A-10 Thunderbolt II aircraft, and will complement the F-22A Raptor (see fig. 1). (2) The short takeoff and vertical landing (STOVL) variant, the F-35B, will be a multirole, stealthy strike fighter that will replace the Marine Corps’ F/A-18C/D Hornet and AV-8B Harrier aircraft. (3) The carrier-suitable variant (CV), the F-35C, will provide the Navy a multirole, stealthy strike aircraft to complement the F/A-18 E/F Super Hornet. The Marine Corps will also field a limited number of F-35C CVs. Lockheed Martin is the aircraft contractor and Pratt & Whitney is the engine contractor. DOD began the F-35 program in October 2001 with a highly concurrent acquisition strategy, resulting in substantial overlap between development, testing, and production. The program was restructured in 2003 and again in 2007 due to performance problems, cost growth, and schedule slips. After the program experienced a critical cost breach in 2010, the program was restructured once more, and in 2012 some near- term procurement quantities were deferred to a future date and the program’s cost estimates were increased. In 2013, DOD issued a report to Congress stating that the Marine Corps, Air Force, and Navy were planning to field initial operational capabilities (IOC) in 2015, 2016, and 2018, respectively. See figure 2 for a timeline of major events leading from the beginning of development. The program is currently in low-rate initial production, and the contractor is assembling the next lot of 36 aircraft with a scheduled delivery by the end of 2015. As of June 2014, 78 aircraft have been fielded, are flying, and are being maintained at Eglin Air Force Base, Marine Corps Air Station Yuma, Edwards Air Force Base, Nellis Air Force Base, and Luke Air Force Base. The program had achieved about 18,250 cumulative flight hours for the fleet of aircraft; a total of 200,000 flight hours are required in order for the fleet to reach R+M maturity, as outlined in the program’s Operational Requirements Document. In March 2014, we found that the program had progressed in its developmental flight testing, but it continued to lag in testing of critical mission-systems software, delaying the delivery of expected warfighting capabilities. By full-rate production, planned for fiscal year 2019, DOD would generally be required to establish adequate sustainment and support systems for the F-35. Per DOD guidance for all weapon systems acquisitions, these sustainment and support systems should be defined in a support concept that is incorporated into a sustainment strategy. For the F-35, this concept should comprise the necessary plans to conduct operations, maintenance, and sustainment throughout the system’s life cycle, with the F-35 Life Cycle Sustainment Plan serving as the principle document governing F-35 sustainment. According to the F-35 Operational Requirements Document, this concept must provide warfighting and peacetime capability with the lowest cost of ownership, and all variants must be able to deploy rapidly, sustain high mission reliability, and sustain a high sortie-generation rate. In developing this strategy, the program has made affordability its top priority, and the F-35 Program Executive Officer reiterated this priority in his April 2014 testimony. In this testimony, the Program Executive Officer also identified areas in which the program is focusing on driving down sustainment costs and identifying improvements to meet long-term sustainment needs in order to “produce a mutually beneficial sustainment enterprise that operates, manages, and supports the global system with relevant metrics and incentives, while meeting warfighter-defined readiness and cost objectives.” However, the department has stated that it has a long history of starting programs that proved to be unaffordable, and the result of this practice has been costly program cancellations and dramatic reductions in inventory objectives. Recently updated DOD acquisition policy has placed more emphasis on including sustainment considerations as early as possible in the acquisition process. According to the policy, a successful program meets the sustainment performance requirements, remains affordable, and continues to seek cost reductions throughout the Operations and Support Phase that begins after the full-rate production decision. In a 2012 memorandum, the Under Secretary of Defense for Acquisitions, Technology and Logistics (AT&L) acknowledged that certain F-35 program areas including the Autonomic Logistics Information System (ALIS), reliability growth, and sustainment costs require additional improvement. ALIS. ALIS is the primary sustainment tool for the F-35 and is intended to predict maintenance and supply issues, automate logistics support processes, and provide decision aids to help reduce life-cycle sustainment costs and improve force readiness. ALIS is one of three major components that make up the F-35 air system, along with the aircraft and the engine, and comprises both hardware and software. The F-35 program is delivering ALIS capabilities incrementally, which include: operations, maintenance, supply chain, customer-support services, training, tech data, system security and external interfaces. Reliability and Maintainability (R+M). R+M measures aircraft performance to determine how often the aircraft experiences failures and how much time it takes to repair those failures. R+M is monitored through a series of metrics that measure the intended performance of the aircraft in meeting its requirements by maturity at a cumulative 200,000 flight hours with at least 50,000 flight hours per variant. R+M drives sortie-generation rates and a reduced logistics footprint for the F-35, as well as informing program O&S costs, which are tied to the performance of the system at maturity. O&S Costs. O&S consists of sustainment costs incurred from the initial system deployment through the end of system operations and includes all costs of operating, maintaining, and supporting a fielded system. The F-35 JPO develops an annual estimate for the O&S costs of maintaining and supporting the F-35 for 56 years.the estimate was $1.03 trillion; in 2012, it was $857 billion; and in 2013, it was $916 billion in then-year dollars. Additionally, CAPE conducts independent cost estimates on certain programs at different points in the acquisition cycle. In recent years, CAPE’s F-35 O&S cost estimate has been reported in DOD’s annual SAR as the official O&S cost estimate for the program. In 2013, that estimate was about $1.02 trillion in then-year dollars. As stated earlier, recent changes to DOD’s acquisition guidance and policy have also focused on making sustainment decisions earlier in the acquisition process, by identifying the attributes of an effective performance-based logistics arrangement and requiring strategies that identify and manage technical data rights. Both of these areas will play an important role in the future of the F-35 program. Performance Based Logistics (PBL).based logistics strategy ties objective metrics for delivered logistical system performance to incentives that will motivate the support provider (i.e., the contractor). In recent years, F-35 program managers have reaffirmed their commitment to employing a robust performance- based logistics system for the F-35 to help determine options for pursuing the most value-driven performance-based agreements with the support provider. Technical Data Rights. Technical data for weapon systems include the details necessary to ensure the adequacy of performance, as well as instructions for operation, maintenance, and other actions needed to support weapon systems. Technical data are an important part of a weapon system program, such as the F-35. Identifying technical data needs and costs early in the acquisition process can help program managers maximize the potential for future competition and develop the system’s overall sustainment strategy. DOD’s development of an F-35 sustainment strategy is an ongoing process that includes a number of plans, analyses, and decisions that must be finalized by the start of full-rate production—estimated to occur in fiscal year 2019. To date, the program’s sustainment strategy continues to evolve but may not be affordable, and DOD has not fully addressed several key risks to long-term affordability and operational readiness, that, if not mitigated, could affect the development of the strategy. DOD has a number of sustainment planning documents that will make up the F-35 program’s overall sustainment strategy, including the Life Cycle Sustainment Plan, which, according to DOD policy, will provide the basis for sustainment activities. DOD also has past and ongoing studies and analyses that have the potential to affect and inform the overall sustainment strategy, including two Business Case Analyses and several Level of Repair Analyses. These planning documents and analyses will provide the basis for the overall sustainment strategy that will dictate sustainment operations when the program enters full-rate production. Furthermore, a recently launched initiative led by the F-35 JPO is working to establish a roadmap to the end of the design phase in 2018, which is intended to eventually result in a Future Support Construct—another element of sustainment planning that will inform decisions for long-term operations and support for the aircraft. The JPO plans to finalize the Future Support Construct in March 2015. However, the current sustainment strategy that DOD is developing may not be affordable.