United States Government Accountability Office

GAO Report to Congressional Committees

JOINT STRIKE 

FIGHTER 

Progress Made and 

Challenges Remain 

March 2007 

 

GAO-07-360 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

March 2007

JOINT STRIKE FIGHTER 

Progress Made and Challenges Remain 

Highlights of GAO-07-360, a report to 

congressional committees 

The Joint Strike Fighter (JSF) 

program—a multinational 

acquisition program for the Air 

Force, Navy, Marine Corps, and 

eight cooperative international

partners—is the Department of 

Defense’s (DOD) most expensive 

aircraft acquisition program. DOD 

currently estimates it will spend 

$623 billion to develop, procure, 

and operate and support the JSF 

fleet. The JSF aircraft, which 

includes a variant design for each 

of the services, represents 90

percent of the remaining planned 

investment for DOD’s major 

tactical aircraft programs. In fiscal

year 2004, the JSF program was 

rebaselined to address technical 

challenges, cost increases, and 

schedule overruns. 

This report—the third mandated by

Congess—describes the program’s 

progress in meeting cost, schedule,

and performance goals since 

rebaselining and identifies various 

challenges the program will likely 

face in meeting these goals in the

future. 

What GAO Recommends

GAO is recommending that DOD 

limit annual production quantities

to no more than 24 aircraft per year 

until each variant’s basic flying

qualities have been demonstrated

in flight testing now scheduled in 

the 2010 time frame. DOD nonconcurred, believing its current 

strategy provides a balance of 

technical risk, financial constraints, 

and operational needs.

The JSF program has delivered and flown the first development aircraft. 

However, cost and schedule goals established in the fiscal year 2004

rebaselined program have not been met. Total JSF program acquisition costs

(through 2027) have increased by $31.6 billion and now DOD will pay 12 

percent more per aircraft than expected in 2004. The program has also 

experienced delays in several key events, including the start of the flight test 

program, delivery of the first production representative development 

aircraft, and testing of critical missions systems. Delays in the delivery of 

initial development aircraft were driven by incomplete engineering drawings, 

changes in design, manufacturing inefficiencies, and parts shortages. Despite

these delays, the program still plans to complete development in 2013, 

compressing the amount of time available for flight testing and development 

activities. Also, the program projects it will meet all but one key 

performance requirement—line of sight communications---that is currently 

dependent on other capabilities being developed outside the JSF program. 

Accurately predicting JSF costs and schedule and ensuring sufficient funding 

will likely be key challenges facing the program in the future. JSF continues 

to pursue a risky acquisition strategy that concurrently develops and 

produces aircraft. While some concurrency may be beneficial to efficiently 

transition from development to production, the degree of overlap is 

significant on this program. Any changes in design and manufacturing that 

require modifications to delivered aircraft or to tooling and manufacturing 

processes would result in increased costs and delays in getting capabilities

to the warfighter. Low-rate initial production will begin this year with almost 

the entire 7-year flight test program remaining to confirm the aircraft design. 

Confidence that investment decisions will deliver expected capability within 

cost and schedule goals increases as testing proves the JSF will work as 

expected. The JSF program also faces funding uncertainties as it will 

demand unprecedented funding over the next 2 decades—more than $12.6 

billion a year on average through 2027. 

Overlap of Production Investments and Testing

Cumulative production 

investment (in billions of dollars) 

Increasing confidence in investment outcomes 

2 14 30 60 103 185 275

$0.9 $3.7 $7.4 $13.5 $20.4 $31.0 $41.9

Percentage of 

flight test program 

completed 

1% 3% 13% 35% 56% 77% 98%

Cumulative aircraft

2007 2008 2009 2010 2011 2012 2013 

Limited knowledge 

gained from flight tests

More knowledge 

gained from flight tests

Source: DOD data, as of February 2007; GAO analysis and presentation.

www.gao.gov/cgi-bin/getrpt?GAO-07-360.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Michael J. 

Sullivan at (202) 512-4841 or 

sullivanm@gao.gov. 
Contents 

Letter 1

Results in Brief 2 

Background 4

Program Cost Estimates Have Increased Significantly and Critical 

Milestones Have Been Delayed Since the JSF Was Rebaselined 6 

Challenges Remain in Executing the Balance of the JSF Program 14 

Conclusions 22

Recommendation for Executive Action 23 

Agency Comments and our Evaluation 23 

Appendix I Scope and Methodology 26 

Appendix II Comments from the Department of Defense 28 

Tables 

Table 1: Changes in JSF Program Purchase Quantities and Costs 5 

Table 2: JSF Cost Estimate Changes since the Rebaseline 7 

Table 3: JSF Program Estimates for Achieving Key Performance 

Parameters 14

Table 4: Comparison between F-22A and Joint Strike Fighter 

Development Programs 18 

Figures 

Figure 1: First JSF Development Aircraft in Flight 9 

Figure 2: Changes in JSF Scheduled Events since the Replan 10 

Figure 3: Manufacturing Efficiency of First Test Aircraft as of 

November 2006 11 

Figure 4: Major Areas of JSF Flight Testing to Be Completed 15 

Figure 5: Notional Illustration Showing the Different Paths That 

JSF Development Can Take 17 

Figure 6: JSF Program’s Annual Funding Requirements 20 

Page i GAO-07-360 Joint Strike Fighter
Abbreviations 

CAIG Cost Analysis and Improvement Group 

DCMA Defense Contract Management Agency 

DOD Department of Defense 

JSF Joint Strike Fighter 

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Page ii GAO-07-360 Joint Strike Fighter
United States Government Accountability Office

Washington, DC 20548 

March 15, 2007 

Congressional Committees 

The Joint Strike Fighter (JSF) is the Department of Defense’s (DOD) most 

expensive aircraft acquisition program. The JSF aircraft design includes 

three variants to be used by the Air Force, Navy, Marine Corps, and eight 

cooperative international partners. JSF is a central part of DOD’s overall 

recapitalization strategy for its tactical aircraft fleet, representing 90 

percent of the remaining planned investment for its major tactical aircraft

programs. DOD currently estimates it will spend $276 billion to develop

and procure about 2,443 aircraft and related support equipment by 2027 

and an additional $347 billion to operate and support these aircraft once 

they have been fielded.

The Ronald W. Reagan National Defense Authorization Act for Fiscal Year 

2005 (P.L. 108-375) requires GAO to review the JSF program annually for 

5 years.1

 In the past 2 years, we issued reports identifying opportunities for 

the program to reduce risks and improve the chance for more successful 

outcomes. We recommended DOD pursue an acquisition strategy 

consistent with best practices and DOD policy preferences regarding 

evolutionary and knowledge-based acquisitions including deferring 

production investments until the aircraft have been proven to work in 

flight testing.2

 DOD has taken no direct actions in response to these 

recommendations and has stated that its current acquisition approach 

fulfills the intent of DOD policy and further limits on production are 

unnecessary. In 2006 Congress reduced the number of production aircraft

to be funded in fiscal year 2007 and the number of aircraft to receive 

advanced procurement funds for aircraft to be procured in fiscal year 

2008. 

 1

 Section 213 of the Act requires us to assess the extent to which the system development

and demonstration program is currently meeting cost, schedule, and performance goals;

the likelihood that the program will be completed within estimated costs; and the 

program’s current acquisition plan leading to production. 

2

 GAO, Joint Strike Fighter: DOD Plans to Enter Production before Testing Demonstrates 

Acceptable Performance, GAO-06-356 (Washington D.C.: Mar. 15, 2006) and Tactical 

Aircraft: Opportunity to Reduce Risks in the Joint Strike Fighter Program with Different 

Acquisition Strategy, GAO-05-271 (Washington D.C.: Mar. 15, 2005). 

Page 1 GAO-07-360 Joint Strike Fighter
This report assesses the progress of the JSF program since it was 

rebaselined in fiscal year 2004 to add resources needed to address 

technical problems. Specifically, we (1) determined the JSF program’s 

progress in meeting cost, schedule, and performance goals; and 

(2) identified the challenges and risk the program will face in meeting 

these goals in the future. We performed our work from June of 2006 to 

March of 2007 in accordance with generally accepted government auditing 

standards. For more information on our scope and methodology, see 

appendix I. 

The Act also requires us to certify whether we had access to sufficient 

information to make informed judgments on the matters contained in our 

report. We were provided sufficient information to measure the program’s 

progress in meeting its goals based on cost data provided in April 2006 as

well as the challenges that remain for the program. At the time of our 

review, DOD was still preparing its new cost estimate to be included in the 

program’s Selected Acquisition Report dated December 31, 2006, expected

to be delivered to the Congress by April 2007. Because the new cost 

estimate for the JSF program will not be available until after this report is 

issued we are unable to make informed judgments on those estimated 

costs. It should be noted that after our 2006 report was issued on March 

15, 2006, DOD released its December 2005 Selected Acquisition Report, 

which showed an increase of over $19 billion in estimated JSF program 

costs. 

The JSF program has delivered and flown the first development aircraft 

and has started manufacturing additional development aircraft for the test 

program. JSF program costs have increased by $31.6 billion since the 

program was rebaselined in fiscal year 2004. As a result, DOD will pay 

more per aircraft than was expected when the program was rebaselined.

The program has also experienced delays in the start of the flight test 

program but has not changed the dates for completing development 

reducing the amount of time available for flight testing and development 

activities. Late design drawings, changes in design and manufacturing 

processes, and late subsystem deliveries caused delays that prevented 

timely manufacturing and delivery of development aircraft. The program 

currently projects that the JSF will meet all but one of its key performance 

requirements—ability to fully interoperate with other platforms. These 

performance projections are based largely on engineering analysis, 

modeling, and laboratory testing and not on flight testing. 

Results in Brief 

Page 2 GAO-07-360 Joint Strike Fighter
The degree of concurrency between development and production in the

JSF program’s acquisition strategy still includes significant risks for cost 

and schedule overruns or late delivery of promised capabilities to the 

warfighter. For example, at the time of the low-rate initial production 

decision, one aircraft will have flown, less than 1 percent of the test 

program will have been completed, and none of the three variants will 

have a production representative prototype built. It will not be until about 

2012 that a fully capable, integrated JSF is scheduled to begin flight 

testing. A 7-year flight test program that includes over 11,000 hours of 

testing just began in December 2006. Therefore, almost all of critical flight

testing remains to confirm that the aircraft will indeed deliver the required 

performance. Manufacturing and technical problems can delay the 

completion of a flight test program, increase the number of flight test 

hours needed to verify that the system will work as intended, and affect 

when capabilities are delivered to the warfighter. The program also faces 

uncertainties with the amount of funding that will be available to support 

the program’s plan. The program will demand unprecedented amounts of 

annual funds over the next 2 decades—more than $12.6 billion a year on 

average. Other DOD review and oversight organizations have expressed 

similar concerns over the level of risk in the program that will challenge 

the completion within estimated cost and schedule. 

To improve chances of a successful outcome, we are recommending that

the Secretary of Defense limit annual production quantities to no more 

than 24 aircraft per year, the current manufacturing capacity, until each

variant’s basic flying qualities have been demonstrated in flight testing 

now scheduled in the 2010 time frame. 

DOD non-concurred with our recommendation stating that the current JSF 

acquisition strategy provides an effective balance of technical risk, 

financial constraints, and operational needs of the services. However, we 

believe DOD’s actions to reduce aircraft quantities in the fiscal year 2008 

President’s Budget are in line with our recommendation to limit 

production to current manufacturing capacity until each variant’s flying 

qualities have been demonstrated in flight testing. In the 2008 budget, 

DOD reduced the number of production aircraft it plans to buy during the 

flight test program by about 35 percent as compared to its previous plan 

for the JSF. Under this new plan DOD does not substantially increase its 

buy quantities of production aircraft until 2011. We continue to believe 

that limiting production quantities until the design is demonstrated would 

reduce the overlap in production and development while still allowing the 

efficient transition from development to production. It would also make 

Page 3 GAO-07-360 Joint Strike Fighter
cost and schedule more predictable and lessen the risk to DOD’s 

production investment. 

JSF is a joint, multinational acquisition program for the Air Force, Navy, 

Marine Corps, and eight cooperative international partners. The program 

began in November 1996 with a 5-year competition between Lockheed 

Martin and Boeing to determine the most capable and affordable 

preliminary aircraft design. Lockheed Martin won the competition, and the 

program entered system development and demonstration in October 2001.

Background 

The program’s objective is to develop and deploy a technically superior 

and affordable fleet of aircraft that support the warfighter in performing a 

wide range of missions in a variety of theaters. The single-seat, singleengine aircraft is being designed to be self-sufficient or part of a 

multisystem and multiservice operation, and to rapidly transition between 

air-to-surface and air-to-air missions while still airborne. To achieve its 

mission, JSF will incorporate low observable technologies, defensive 

avionics, advanced onboard and offboard sensor fusion, internal and 

external weapons, and advanced prognostic maintenance capability. 

According to DOD, these technologies represent a quantum leap over 

legacy tactical aircraft capabilities. At the same time, the JSF aircraft 

design includes three variants: a conventional take-off and landing variant

for the Air Force; an aircraft carrier-suitable variant for the Navy; and a 

short take-off and vertical landing variant for the Marine Corps and the 

United Kingdom. JSF is intended to replace a substantial number of aging

fighter and attack aircraft in DOD’s current inventory. 

In 2003 the JSF program system integration efforts and a preliminary 

design review revealed significant airframe weight problems that affected 

the aircraft’s ability to meet key performance requirements. Software 

development and integration also posed a significant development 

challenge. The program’s inability to meet its ambitious goals resulted in 

the Department’s failing to deliver on the business case that justified initial 

investment in JSF. As a result, purchase quantities have been reduced, 

total program costs have increased, and delivery of the initial aircraft has 

been delayed. These changes have effectively reduced DOD’s buying 

power for its investment as it will now be buying fewer aircraft for a 

greater financial investment. It is too late for the program to meet these 

initial promises. To its credit, in fiscal year 2004, DOD rebaselined the 

program extending development by 18 months and adding resources to 

address problems discovered during systems integration and the 

preliminary design review. Program officials also delayed the critical 

design reviews, first flights of development aircraft, and the low-rate initial 

Page 4 GAO-07-360 Joint Strike Fighter
production decision to allow more time to mitigate design risk and gather

more knowledge before continuing to make major investments. Table 1 

shows the evolution of cost and delivery estimates from the start of the 

program up to the latest official program information as of December 

2005. 

Table 1: Changes in JSF Program Purchase Quantities and Costs 

November 1996

(program start)

October 2001

(system

development start)

December 2003a 

(rebaseline) 

December 2005a

(latest

 available data)

Expected Quantities 

Development quantities 10 14 14 15

Procurement quantities (U.S. only) 2,978 2,852 2,443 2,443

Total Quantities 2,988 2,866 2,457 2,458

Cost Estimates (Then Year $ in billions) 

Development $24.8 $34.4 $44.8 $44.5

Procurement Not available 196.6 199.8 231.7

Other Not available 2.0 0.2 0.2

Total Program Acquisition Not available $233.0 $244.8 $276.5b

Unit Cost Estimates (Then Year $ in millions) 

Program acquisition Not available $81 $100 $112

Average procurement Not available 69 82 95

Estimated Delivery Dates 

First operational aircraft delivery 2007 2008 2009 2009

Initial operational capability 2010 2010-2012 2012-2013 2012-2015c

Source: GAO analysis of DOD data. 

a

The Selected Acquisition Reports are dated December 2003 and 2005 but are not officially released 

until March or April of the following year. 

b

Numbers may not add due to rounding. 

c

Recent program and President’s budget information indicates that initial operational capability for the

Navy’s carrier variant has been rescheduled from the second quarter of 2013 to the first quarter of

2015. 

Page 5 GAO-07-360 Joint Strike Fighter
Since establishing a new program baseline in fiscal year 2004, JSF program 

costs have risen and key events have been delayed. JSF program costs 

have increased by $31.6 billion since the program’s decision to rebaseline 

in fiscal year 2004. This includes a $19.8 billion increase in costs since our 

report last year in March 2006. The program has experienced delays in 

several key events including delays in the start of the flight test program, 

manufacturing and delivery of the first development aircraft, and delays in

the testing of critical missions systems. These delays reduce the amount of

time available for completing flight testing and development activities. The 

program projects that it will meet its key performance requirements 

except for one dealing with the warfighter’s ability to fully interoperate 

with other platforms. Projections are based largely on engineering 

analysis, modeling, and laboratory testing, and a 7-year test program to 

demonstrate performance just started in December 2006. 

JSF program cost estimates have increased by $31.6 billion since the 

program’s decision to rebaseline in fiscal year 2004. During this period, 

estimates in some cost areas grew by $48 billion but were offset by 

$16.4 billion due to quantity changes and the proposed termination of an 

alternate engine program. According to the program, the cost estimate is 

still mostly based on cost estimating relationships—like cost per pound—

not actual costs and, therefore, is subject to change as the program 

captures the actual costs to manufacture the aircraft. Also, the official 

program estimate is based on the program’s December 31, 2005, Selected 

Acquisition Report delivered to Congress in April 2006. We could not 

review the most recent estimated costs of the JSF program. This 

information is being used by the Office of the Secretary of Defense in 

preparing its fiscal year 2008 budget request as well as for the program’s 

Selected Acquisition Report dated December 31, 2006, expected to be 

delivered to the Congress in early April 2007. Although the most recent 

estimates were not available for this review, we expect that, unless 

program content is changed, future cost estimates will be higher based on 

the history of similar acquisition programs and the risks that remain in the

program. Table 2 shows the changes to the program’s costs since the 

rebaseline in fiscal year 2004. 

Program Cost 

Estimates Have 

Increased 

Significantly and 

Critical Milestones 

Have Been Delayed 

Since the JSF Was 

Rebaselined 

Total Program Cost

Estimates Have Increased 

Page 6 GAO-07-360 Joint Strike Fighter
Table 2: JSF Cost Estimate Changes since the Rebaseline 

(Then-year dollars in billions) 

Research, development, 

test and evaluation Procurement Total

December 2003 estimated costs $44.8 $199.8 $244.6a

Cost growth 1.8 46.2 48.0

Cost reductions (2.1) (14.3) (16.4)

Elimination of alternate engine program (2.1) (5.1) (7.2)

Benefits from including partner quantities — (9.2) (9.2)

December 2005 estimated costs $44.5 $231.7 $276.2a

Dollar change $(0.3) $31.9 $31.6

Percent change (0.6) 16 13

Source: GAO analysis of DOD data. 

a

Does not include estimated military construction costs.

Since our last report, the program estimated a $19.8 billion net increase in 

its total program costs. The majority of the cost growth, over 95 percent, 

was for procurement. According to the program office, several factors led 

to an increase in the procurement cost estimate. The most significant 

increases include: 

• $10.3 billion—result of design and manufacturing changes to large 

bulkheads in the wing section of the aircraft, need for 6 times more 

aluminum and almost 4 times more titanium than originally estimated. 

At the same time, titanium costs almost doubled.

• $3.5 billion—result of reduced manufacturing efficiency because of 

plans to build a certain number of wings at a new subcontractor. 

• $5.5 billion—result of changing the business relationship of the prime 

and two major subcontractors. 

• $4.4 billion—result of projected higher support costs. 

• $14.7 billion—result of changing assumptions for estimating labor rates 

and inflation. 

The increases in procurement costs were offset by two main factors. First, 

the cost estimate reflects production efficiency benefits of $9.2 billion 

from producing 508 international partner aircraft that were not included in

previous estimates. Secondly, the program reduced procurement costs by 

$5.1 billion as a result of the proposed elimination of the alternate engine

program. According to the program office, it expected savings from 

manufacturing efficiencies by having one engine contractor producing a 

larger quantity of engines. Program officials stated that they have had 

difficulty quantifying cost savings that might accrue from competing 

Page 7 GAO-07-360 Joint Strike Fighter
engine buys between contractors. For now Congress has reinstated the 

alternate engine program and has required further analysis from DOD and 

others on the costs of the program.3

The program also reported that development costs decreased by 

$1.2 billion. The reduction in development costs was due almost entirely to

the removal of the remaining estimated costs to complete the alternate 

engine’s development. Again, Congress has since reinstated funding for the 

alternate engine program. 

The net effect of the JSF program cost increases is that DOD will pay more 

per aircraft than expected when the program was rebaselined. The average 

procurement unit costs have increased from $82 million to almost 

$95 million and the program acquisition unit costs has increased from 

$100 million to over $112 million. 

Delays in Key Program 

Events Have Compressed 

the Development Schedule 

Since the JSF program was rebaselined, it has experienced delays in 

several key development activities but without corresponding changes to

the end of development. Holding firm to these dates forces the program to 

find ways to complete development activities in less time, especially if 

problems are discovered in the remaining 6 years of development. The 

program office is evaluating different ways to reduce the risk of this 

compression by being more efficient in its flight test activities. The first 

JSF flight was scheduled for August 2006 but did not occur until mid 

December 2006—about 4 months later than expected. According to the 

program office, the first flight was successful but was shortened because 

of a problem with instrumentation on the aircraft. Although the first 

aircraft will be able to demonstrate some performance—limited flying 

qualities, propulsion, and vehicle subsystems—it is not a production 

representative aircraft with fully functioning critical mission systems or 

the design changes from the rebaselined program that reduced airframe 

weight. 

 3

 In section 211 of the John Warner National Defense Authorization Act for Fiscal Year 2007 

(P.L. 109-364), Congress required independent cost analyses of the alternate engine 

program by March 15, 2007, from the DOD Cost Analysis Improvement Group, a Federally 

Funded Research and Development Center selected by DOD, as well as GAO. 

Page 8 GAO-07-360 Joint Strike Fighter
Figure 1: First JSF Development Aircraft in Flight

Source: JSF program office.

The first flight of a production representative aircraft has been delayed 

8 months to May 2008. This aircraft will be a short take-off and vertical

landing variant and will incorporate the design changes from the 

rebaselined program. According to the latest program information, the 

first fully integrated, capable JSF is scheduled to begin testing in the early

2012 time frame, a delay of several months. The first flight of a JSF with 

limited mission capability has been delayed 9 months. The estimate for 

first flight of a production representative conventional take-off variant has

been delayed 11 months to January 2009 and the first flight of a carrier 

variant has been delayed by as much as 4 months to May 2009. 

The flying test bed, also critical to reducing risk in the flight test program, 

has been delayed about 14 months to late 2007. This aircraft is a modified 

Boeing 737 that will be equipped with the sensors and mission system 

software and hardware. The test bed will allow the program to test aircraft 

mission systems such as target tracking and detection, electronic warfare, 

and communications. Figure 2 shows schedule delays and the 

compression in the development schedule. 

Page 9 GAO-07-360 Joint Strike Fighter
Figure 2: Changes in JSF Scheduled Events since the Replan

Delivery of first early

prototype and the 

start of flight test

program

Source: DOD (2007 data); GAO (analysis and presentation).

2006 2007 2008 2009 2010 2011 2012 2013

First flight of test bed

(a 737 air frame)

Delivery of first 

production-represenative test aircraft

Short take-off/

vertical landing

Conventional

take-off/landing

Carrier variant

Delivery of first

mission system

test aircraft

Delivery of first fully

integrated, capable

test aircraft

Event did not or has not occurred

Event has occurred

New date for event

Period of flight testing

End of development; start of full-rate production

Future schedule for flight

testing and product

development is

compressed

Design and Manufacturing 

of Development Aircraft 

Has Been a Major Source 

of Delay 

The program has completed manufacturing of its first development 

aircraft and manufacturing data indicates that the program did not meet its 

planned labor hour goals. Manufacturing data on subsequent development 

aircraft that have begun manufacturing indicate these aircraft are not 

currently meeting their planned manufacturing efficiencies either. 

According to contractor data as of November 2006, the first development 

aircraft had required 35 percent or 65,113 more labor hours than expected. 

The program encountered most of the inefficiencies in the mate and 

delivery phase and with the fabrication of the center fuselage and wing. 

Page 10 GAO-07-360 Joint Strike Fighter
Figure 3 shows the planned hours versus the actual hours needed for 

completing the first test aircraft. 

Figure 3: Manufacturing Efficiency of First Test Aircraft as of November 2006 

0

50,000

100,000

150,000

200,000

250,000

300,000

Planned Actual

Labor hours

Source: Lockheed Martin (data), GAO (analysis).

185,400

250,513

When the first aircraft began manufacturing, the program had released 

about 20 percent of the engineering drawings needed for building the 

aircraft. This led to a backlog of drawings, negatively impacting the 

availability of parts needed for efficient manufacturing operations. To 

compensate for delays and parts shortages for production, components of 

the aircraft were manufactured out of sequence and at different 

manufacturing workstations than planned. For example, the wing section 

was mated to the center fuselage before work on the wing was completed. 

The wing was only 46 percent complete and still required more than 

18,500 hours of work. Because this remaining work was completed at a 

different workstation than was planned, contractor officials stated that 

major tooling—such as a stand that supports the wing structure upright to

allow workers to install wiring and other parts—was not available for use.

As a result, workers were required to lie on the ground or bend under or 

over the wing structure to complete the wing assembly, significantly 

increasing the number of hours needed to complete this effort. According 

to Defense Contract Management Agency, out-of-station work performed 

on the wing required an additional 46 percent more hours than planned. 

Late delivery of parts and late qualification of subsystems were the major 

Page 11 GAO-07-360 Joint Strike Fighter
drivers to the mate and delivery inefficiencies, more than doubling the 

hours needed to complete this activity. 

Lockheed Martin, the prime contractor, appears to be focused on 

developing an efficient and effective manufacturing process for the JSF, 

but it is still very early in that process. The development aircraft now in 

manufacturing are not currently meeting their planned efficiencies. As 

with the first test aircraft, the program does not expect to manufacture the 

development aircraft in the planned manufacturing sequence. The program 

expects to move some wing fabrication activities to final assembly and do 

both fabrication and final assembly concurrently. Early development 

aircraft are already experiencing inefficiencies and delays. As of December 

2006, wing manufacturing data for one of these aircraft shows the program 

had completed less than 50 percent of the activities expected at this time 

while requiring 41 percent more hours than planned. According to the 

contractor and program officials, these inefficiencies are largely due to 

late delivery of the wing bulkheads because of a change in their 

manufacturing process. The Defense Contract Management Agency has 

rated manufacturing as high risk, stating that the primary cause of risk is 

the late delivery of parts to properly support the manufacturing work flow. 

It projects further delays to schedule, increased costs, and subsequent outof-sequence work. 

An early indicator of design stability is the completion of design drawings 

at the critical design review. In February 2006, the program held its critical 

design review for production representative conventional and short takeoff and vertical landing aircraft.4

 At that time, the program had completed

47 percent of the short take-off aircraft design and 3 percent of the 

conventional aircraft design. Our previous best practices work suggests 

that completion of 90 percent of a product’s engineering drawings 

provides tangible evidence that the design is stable. As with the first 

aircraft, the program has experienced late releases of engineering 

drawings, which has delayed the delivery of critical parts from suppliers to 

manufacturing for the building of the initial aircraft. For example, based 

on program data as of October 2006, more than one-third of the drawings 

needed to complete these two variants are expected to be released late to

manufacturing. 

 4

 Critical design review for the carrier variant has been rescheduled from late 2006 to 

spring 2007. According to program officials, this delay will allow the program to mature the 

design of the variant. 

Page 12 GAO-07-360 Joint Strike Fighter
Although the first aircraft encountered manufacturing inefficiencies, the 

JSF Program and the contractor have pointed to some successes in this 

initial manufacturing effort. For example, they have stated the mate of the 

major sections of the aircraft was more efficient than in past aircraft 

programs because of the state-of-the-art tools used to design the aircraft 

and develop the manufacturing process. Likewise, they have indicated that 

they have experienced fewer defects in this first aircraft than experienced

on legacy aircraft. 

We would agree that the contractor has made progress in demonstrating 

the use of several large tools and fabrication processes in building the first 

test aircraft. However, a key factor in developing an efficient and effective 

manufacturing process is a mature aircraft design. Major design 

modifications can cause substantial and costly changes in the

manufacturing process. For example, since the first aircraft entered 

production, the manufacturing process has had to be altered due to 

redesigning required to resolve weight and performance problems. 

According to Defense Contract Management Agency officials, some tools 

already bought and in place were either no longer useful or being used less 

efficiently. New tools had to be procured and the manufacturing process 

had to change. The Defense Contract Management Agency noted that 

these additional tooling costs were about $156 million. Contractor officials 

stated that the current manufacturing capacity is sufficient to produce 

about 24 aircraft per year. Given that only one aircraft has been built and

essentially all of the flight and static and durability testing remains to be 

done there is still significant risk that the JSF design for each of the three 

variants will incur more changes as more design knowledge is gained. 

The JSF Program Projects 

Key Performance 

Parameters Will Be Met 

Based on Modeling and 

Simulations 

Currently, the JSF program estimates that by the time the development 

program ends the aircraft design will meet all but one of its key 

performance parameters. The performance estimates to date are based on 

engineering analyses, computer models, and laboratory tests. Key 

performance parameters are defined as the minimum attributes or 

characteristics considered most essential for an effective military 

capability—for the JSF there are eight parameters. The program office 

estimates that seven of the eight key performance parameters are being 

met. The aircraft is currently not meeting its full interoperability 

performance parameter due to a requirement for beyond-line-of-sight 

communications. Meeting the full interoperability required is currently 

dependent on other capabilities being developed outside the JSF program. 

Most ground and flight tests will have to be completed before all the key 

performance estimates are confirmed. At this time, the program has 

Page 13 GAO-07-360 Joint Strike Fighter
completed less than 1 percent of the flight test program and no structural 

or durability tests have been started. According to the program’s test and 

evaluation master plan, the key performance parameters will be verified 

during testing from 2010 to 2013. Table 3 shows the program’s estimate for 

each key performance parameter. 

Table 3: JSF Program Estimates for Achieving Key Performance Parameters 

Status Confirmed through flight testing 

Key performance parameter Meeting Not meeting Yes No

Combat radius 

CV Recovery 

STOVL Performance 

Interoperability 

Radio frequency signature 

Mission reliability 

Sortie Generation Rate 

Logistics footprint 

Source: GAO analysis of JSF program office data.

The JSF program’s acquisition strategy includes significant challenges to 

achieve projected cost and schedule goals. The program has begun 

procurement but not yet demonstrated that the aircraft design is mature, 

can be manufactured efficiently, and delivered on time. The flight test 

program has just begun, and there is always risk of problems surfacing and 

causing further delays. The degree of concurrency between development 

and production in the JSF program’s acquisition strategy still includes 

significant risks for cost and schedule overruns or late delivery of 

promised capabilities to the warfighter. The program also faces 

uncertainties with the amount of funding that will be available to support 

the program’s plan. Other DOD review and oversight organizations have 

also expressed concern over the level of risk in the program and the 

resulting costs that will be incurred to complete this acquisition program. 

The program has planned a 7-year flight test program that includes over 

11,000 hours of testing and over 6,000 flights. This is 75 percent more than 

the F-22A’s flight test program and more than double the F/A-18E/F testing 

efforts. As of this report, the flight test program was only beginning with

essentially all critical flight testing remaining to confirm that the aircraft 

Challenges Remain in 

Executing the 

Balance of the JSF 

Program 

Challenges to Complete 

Flight Testing 

Page 14 GAO-07-360 Joint Strike Fighter
will indeed deliver the required performance. Figure 4 shows the planned 

flight tests by major test categories. 

Figure 4: Major Areas of JSF Flight Testing to Be Completed 

0

200

400

600

800

1,000

1,200

1,400

Armament

Survivability

Mission systems

Shipboard tests

CV flight

S

performance

TOVL flight

performance

CTOL flight

performance

Number of flights

Source: Lockheed Martin (data), GAO (analysis).

Major test categories

1,089

1,371

895

360

573

230

628

The JSF variants possess significant similarities—all designed to have low 

observable airframe characteristics, fly at supersonic speeds, shoot air-toair missiles, and drop bombs on target—but each variant has unique 

performance goals to support the services’ different operational concepts 

and environments. Test officials acknowledge that each variant will 

require separate flight testing to demonstrate that it will fly as intended. 

About two-thirds of the flight tests are planned for demonstrating the 

performance of each aircraft design. The other one-third of the flight tests 

are expected to confirm shipboard operations, mission systems, 

survivability, and armament. 

Manufacturing and technical problems can delay the completion of a flight 

test program, increase the number of flight test hours needed to verify that

the system will work as intended, and affect scheduled delivery to the 

warfighter. Under the current testing schedule, the JSF program plans to 

Page 15 GAO-07-360 Joint Strike Fighter
manufacture and deliver 15 flight test aircraft and 7 ground test articles in 

5 years—an aggressive schedule when compared with other programs 

with fewer variables. For example, the F-22A program took almost 8 years 

to manufacture and deliver nine flight test aircraft and two ground test 

articles of a single aircraft design. When the B-2 program began flight 

testing in July 1989, it estimated that the flight test program would last 

approximately 4.5 years and require about 3,600 flight test hours. When the 

test program ended in 1997, the flight test hours had grown to 5,000 hours, 

or by 40 percent, over an 8-year period. Program officials cited several 

causes, including difficulties in manufacturing test aircraft and correcting 

deficiencies from problems discovered during testing. The F-22A 

encountered similar delays increasing a planned 4-year flight test program 

to about 8 years, affecting the program’s ability to conduct operational 

testing and move into production on schedule. As discussed earlier, 

current JSF schedules are already showing that delivery of early test 

aircraft will be later than the planned delivery date. 

The flight test program will also hinge on the delivering aircraft with the 

expected capabilities. JSF’s expected capabilities are largely dependent on 

software that supports vehicle and mission systems. The program plans to 

develop over 22 million lines of code—more than 6 times the lines of code 

needed for the F-22A—in five blocks. The first block is nearly complete 

and the last block is scheduled for completion in late 2011. The program 

has completed less than 40 percent of the software needed for the system’s 

full functionality. Most of the completed software is designed to operate 

the aircraft’s flying capabilities, while much of the remaining software 

development includes software needed for mission capability, including

weapons integration and the fusion of information from onboard sensors 

and sources off the aircraft. Past programs have encountered difficulties in

developing software, which delayed flight test schedules. JSF program 

officials acknowledged that the software effort will become particularly 

challenging during 2007 and 2008 when all five software blocks will be in 

development at the same time. 

Challenges Created by 

Continued Concurrent 

Development and 

Production 

The concurrency between development and production in DOD’s 

acquisition strategy for JSF did not substantially change as a result of the 

program’s rebaseline in fiscal year 2004. Therefore, the program is entering 

low-rate initial production without demonstrating through flight testing 

that (1) the aircraft’s flying qualities function within the parameters of the 

flight envelope—that is, the set limits for altitude, speed, and angles of 

attack; (2) the aircraft design is reliable; or (3) a fully integrated and 

capable aircraft system can perform as intended. Starting production 

Page 16 GAO-07-360 Joint Strike Fighter
before ensuring design maturity through flight testing significantly 

increases the risk because of the of costly design changes that will push 

the program over budget and behind schedule. Failure to capture key 

design knowledge before producing aircraft in quantity can lead to 

problems that eventually cascade and become magnified through the 

product development and production phases. Figure 5 is a notional 

illustration showing the impacts that can result from a highly concurrent 

acquisition strategy to one with less concurrency and that captures key 

design and manufacturing data before production begins. 

Figure 5: Notional Illustration Showing the Different Paths That JSF Development Can Take 

Cost/

investment

Schedule/time

Stable design

Unstable

design

Demonstrated

Late drawings and

design changes

Tooling and design

changes

Fully integrated

aircraft not built

or tested

Production

manufactoring

processes not

in control

Labor inefficiencies

and quality issues

Mature product

Continual

changes needed

to reach maturity

Built and tested

Manufacturing

processes in

control

Likely outcome of highly concurrent program

Likely outcome of minimally concurrent program

Source: GAO.

Page 17 GAO-07-360 Joint Strike Fighter
While some concurrency may be beneficial to efficiently transition from 

the development stage of a program to production, the JSF is currently 

planned to be significantly more concurrent than the F-22A program that 

failed to deliver the warfighting capability on time and at predicted costs. 

Table 4 provides a more detailed comparison between the JSF and F-22A 

development programs and the accomplishments and requirements before 

starting production in each program. 

Table 4: Comparison between F-22A and Joint Strike Fighter Development Programs 

Status of Flight Test Programs at the Start of Low

Rate Initial Production

F-22A Joint Strike Fighter 

Point When Joint Strike

 Fighter Will Match Similar

F-22A Accomplishments

Flight test program accomplished

Flight test hours Approximately 1,300 Approximately 30 2008

Percent of flight test hours 20 percent Less than 1 percent 2009

Number of flight test aircraft delivered 6 of 9 1 of 15 2009

Months of flight testing 48 3 2010

Key test events accomplished

Initiated fatigue testing Yes No 2008

Initiated separation of weapons testing Yes No 2009

Initiated radar cross section testing Yes No 2009

Full scale static testing Yes No 2009

First flight of fully integrated aircraft Yes No 2012

Source: GAO analysis of DOD data. 

As a result of the risk associated with highly concurrent development and 

production, the JSF program plans to place initial production orders on 

cost reimbursement contracts. Cost reimbursement contracts provide for 

payment of allowable incurred costs, to the extent prescribed in the 

contract. Such contracts are used when costs cannot be estimated with 

sufficient accuracy to use any type of fixed price contract. Cost 

reimbursement contracts place a substantial risk on the buyer—in this 

case DOD—because the contractor’s responsibility for the cost risks of 

performance has been minimized or reduced. As knowledge is gained over 

time, the program office intended to shift the contract type to one where 

more cost risk is placed on the contractor. However, DOD materials 

supporting the President’s fiscal year 2008 budget show that all low rate 

production orders will be placed on cost reimbursement contracts. 

Page 18 GAO-07-360 Joint Strike Fighter
To execute its current plan, the JSF program must obtain unprecedented

levels of annual funding—on average over $12.6 billion annually in 

acquisition funds over the next 2 decades. Regardless of likely increases in

program costs, the sizeable continued investment in JSF—estimated at 

roughly $252 billion over 20 years—must be viewed within the context of 

the fiscal imbalance facing the nation within the next 10 years. The JSF 

program will have to compete with many other large defense programs, 

such as the Army’s Future Combat System and the Missile Defense 

Agency’s ballistic missile defense system, for funding during this same 

time frame. There are also important competing priorities external to 

DOD’s budget. Fully funding specific programs or activities will 

undoubtedly create shortfalls in others. 

Unprecedented Funding 

Requirements Could 

Challenge Program 

Execution 

Funding challenges will be even greater if the program fails to achieve 

current cost and schedule estimates for the revised program baseline. The 

consequences of an even modest cost increase or schedule delay on a 

program this size is dramatic. For example, since the program rebaseline 

in fiscal year 2004, the estimated annual funding requirements have 

increased every year from 2012 to 2027 by at least $1 billion and in some 

cases by $3 to $7 billion. These funding increases would be enough to fund 

several major programs’ activities. Figure 6 shows growth in estimated 

annual funding requirements from December 2003 to December 2005. 

Page 19 GAO-07-360 Joint Strike Fighter
Figure 6: JSF Program’s Annual Funding Requirements 

Dollars in billions

0

2

4

6

8

10

12

14

16

18

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Source: GAO analysis of DOD data.

Fiscal year

December 2003

December 2005

9.0

15.8

13.6 13.9 13.8 13.9 14.0 14.2 14.3 14.5 14.0 13.6

10.6 10.0 10.0

9.3

14.3

6.1

7.3

9.9 9.5

Due to affordability pressures, DOD is beginning to reduce procurement 

budgets and annual quantities. The just-released fiscal year 2008 defense 

budget shows declining procurement quantities for the first years of 

production. To meet future constrained acquisition budgets, Air Force and 

Navy officials and planning documents suggest a decrease in maximum 

annual buy quantities from 160 shown in the current program of record to

about 115 per year, a 28 percent decrease. While this will reduce annual 

funding requirements, it will also stretch the procurement program at least 

7 years to 2034, assuming buy quantities are deferred rather than 

eliminated. 

DOD Organizations Have 

Raised Concerns about 

Program Risks and 

Estimated Costs 

DOD’s military service operational test organizations, the Cost Analysis 

and Improvement Group (CAIG), and the Defense Contract Management 

Agency (DCMA) have expressed concerns over the level of risk and 

estimated costs of the program. These oversight and testing organizations 

highlight some of the program risks and the challenges the JSF program 

must overcome to avoid further slips in schedule and more cost growth. 

Page 20 GAO-07-360 Joint Strike Fighter
A February 2006 operational assessment of the JSF program by Air Force, 

Navy and United Kingdom operational test officials noted several areas of 

risk. According to the test report, several of these issues, if not adequately 

addressed, are likely to pose substantial or severe operational impact to 

the JSF’s mission capabilities. Key concerns raised in the report include 

the following: 

• Software development and testing schedules are success-oriented and 

have little margin to accommodate delays. 

• Developmental flight test schedule provides little capability to respond 

to unforeseen problems and still meet scheduled start of operational 

testing. This threatens to slip operational testing and initial operational 

capability. 

• Predicted maintenance times for propulsion system support, integrated 

combat turn, and gun removal and installation do not meet 

requirements. 

• Design requirements to preserve volume, power, and cooling for future 

growth are in jeopardy and will limit capability to meet future 

requirements. 

• Certain technical challenges in the aircraft or its subsystem design that 

could impact operational capability. 

In a follow-up discussion on the report, test officials stated that these 

concerns were still current and they had not been informed by the 

program office of planned actions to address them. The December 2006 

Annual Report of DOD’s Director, Operational Test and Evaluation 

recommended that the JSF program follow up on these issues. 

The CAIG has expressed concerns about the reality of estimated program 

costs. Its preliminary cost estimate in 2005 was substantially higher than 

the program office estimate. The CAIG cited costs associated with mission 

systems, system test, engines, and commonality as drivers in the 

difference between its estimate and that of the program office. According

to discussions in 2006 with CAIG officials, they still have concerns and 

continue to expect program costs to be much higher than the program 

office’s current estimate. The CAIG is not required to submit its next 

formal independent cost estimate until the preparations for Milestone C, 

which for the JSF program is full-rate production. For major defense 

acquisition programs, this milestone generally should occur before lowrate initial production. Milestone C is scheduled for late 2013. 

DCMA’s concerns focus on the prime contractor’s ability to achieve its 

cost and schedule estimates. DCMA, responsible for monitoring the prime 

Page 21 GAO-07-360 Joint Strike Fighter
contractor’s development and procurement activities, found that delays in

aircraft deliveries and critical technical review milestones put at risk the 

contractor’s ability to meet the current schedule. DCMA also identified 

manufacturing operations as a high-risk area highlighting issues with parts 

delivery, raw material availability, and subcontractor performance. Finally, 

it raised concerns with contractor cost growth stating that the contractor

has shown continuing and steady increases since development started, 

even after the contract’s target price was increased by $6 billion as part of

the program’s rebaseline. As of November 2006, DCMA projects that the 

contractor’s current estimated development costs will increase by about 

$1 billion. 

The JSF is entering its 6th year of a 12-year development program and is 

also entering production. The development team has achieved first flight 

and has overcome major design problems found earlier in development. In

addition, the department counts on this aircraft to bear the brunt of its 

recapitalization plans. Therefore, we believe the program is critical to the

department’s future plans and is viable, given progress made to date. 

However, the current acquisition strategy still reflects very significant risk

that both development and procurement costs will increase and aircraft

will take longer to deliver to the warfighter than currently planned. Even 

as the JSF program enters the mid point of its development, it continues to

encounter significant cost overruns and schedule delays because the 

program has continued to move forward into procurement before it has 

knowledge that the aircraft’s design and manufacturing processes are 

stable. Although some of the additional costs were predictable, other 

costs, especially those resulting from rework, represent waste the 

Department can ill afford. 

Conclusions 

Flight testing began just a few months before the decision to begin lowrate initial production. The challenges and risks facing the program are 

only expected to increase as the program begins to ramp up its production 

capabilities while completing design integration, software design, and 

testing. DOD’s approval to enter low-rate initial production this year 

committed the program to this high risk strategy. If the program is unable 

to mitigate risks, its only options will be to reduce program requirements 

or delay when the program achieves initial operational capability. We see 

two ways this risk can be reduced: (1) reducing the number of aircraft for 

procurement before testing demonstrates their performance capabilities, 

thereby reducing the potential for costly changes to the aircraft and 

manufacturing processes or (2) reexamining the required capabilities for 

Page 22 GAO-07-360 Joint Strike Fighter
initial variants with an eye toward bringing them up to higher capability in 

the future. 

Last year Congress reduced funding for the first two low-rate production 

lots of aircraft thereby slowing the ramp up of production. This was a 

positive first step in lowering risk during the early years of testing. 

However, a significant amount of ground and flight tests remains over the 

next 6 years. All three variants need to demonstrate their flight

performance. The carrier variant will be the last of the three variants to be

delivered to the flight test program. It is now scheduled to start flight 

testing in May 2009 and has nearly 900 flight tests planned to demonstrate 

its flight performance. If the program executes its plan for a steep ramp 

up in production before proving the basic flying qualities of each aircraft 

variant, the likelihood of costly changes to its significant investment in 

production will remain high. 

To improve chances of a successful outcome, we are recommending that

the Secretary of Defense limit annual low-rate initial production quantities 

to no more than 24 aircraft per year, the current manufacturing capacity,

until each variant’s basic flying qualities have been demonstrated in flight 

testing now scheduled in the 2010 time frame. 

DOD provided us with written comments on a draft of this report. The 

comments appear in appendix II. 

DOD non-concurred with our recommendation stating that the current JSF 

acquisition strategy provides an effective balance of technical risk, 

financial constraints, and operational needs of the services. However, we 

believe DOD’s actions to reduce aircraft quantities in the fiscal year 2008 

President’s Budget are in line with our recommendation to limit 

production to current manufacturing capacity until each variant’s flying 

qualities have been demonstrated in flight testing. In the 2008 budget, 

DOD reduced the number of production aircraft it plans to buy during the 

flight test program by about 35 percent as compared to its previous plan 

for the JSF. Under this new plan DOD does not substantially increase its 

buy quantities of production aircraft until 2011. We continue to believe 

that limiting production quantities until the design is demonstrated would 

reduce the overlap in production and development while still allowing the 

efficient transition from development to production. It would also make 

cost and schedule more predictable and lessen the risk to DOD’s 

production investment. The JSF program is still only in its sixth year of a 

Recommendation for 

Executive Action 

Agency Comments 

and our Evaluation 

Page 23 GAO-07-360 Joint Strike Fighter
12-year development program with significant challenges remaining such 

as completing the design, software development, and flight testing. As 

such, there is continued risk that testing will not go as planned and 

demonstrating the aircraft’s capability could be delayed beyond the 

current plan. Therefore, we maintain our recommendation and will 

continue to monitor the progress in the test program and the resulting 

dynamics between development and production.

We are sending copies of this report to the Secretary of Defense; the 

Secretaries of the Air Force, Army, and Navy; and the Director of the 

Office of Management and Budget. We will also provide copies to others 

on request. In addition, the report will be made available at no charge on 

the GAO Web site at http://www.gao.gov. 

If you or your staff have any questions concerning this report, please 

contact me at (202) 512-4841. Contact points for our offices of 

Congressional Relations and Public Affairs may be found on the last page 

of this report. Other staff making key contributions to this report were 

Michael Hazard, Assistant Director; Lily Chin; Matthew Lea; Gary 

Middleton; Daniel Novillo; Karen Sloan; Brian Smith, Adam Vodraska; and 

Joe Zamoyta.

Michael J. Sullivan 

Director 

Acquisition and Sourcing Management 

Page 24 GAO-07-360 Joint Strike Fighter
List of Congressional Committees

The Honorable Carl Levin 

Chairman 

The Honorable John McCain 

Ranking Minority Member 

Committee on Armed Services 

United States Senate 

The Honorable Daniel K. Inouye 

Chairman 

The Honorable Ted Stevens 

Ranking Minority Member 

Subcommittee on Defense 

Committee on Appropriations 

United States Senate 

The Honorable Ike Skelton 

Chairman 

The Honorable Duncan L. Hunter 

Ranking Minority Member 

Committee on Armed Services 

House of Representatives 

The Honorable John P. Murtha 

Chairman 

The Honorable C.W. Bill Young 

Ranking Minority Member 

Subcommittee on Defense 

Committee on Appropriations 

House of Representatives 

Page 25 GAO-07-360 Joint Strike Fighter
Appendix I: Scope and Methodology Appendix I: Scope and Methodology 

To determine the status of the Joint Strike Fighter (JSF) program’s cost, 

schedule, and performance, we compared current program estimates 

against estimates established after the program rebaselined in fiscal year 

2004. Current official program cost estimates are based on the program’s 

December 31, 2005, Selected Acquisition Report to Congress. At the time 

of our review, the Office of the Secretary of Defense was still preparing its 

new cost estimate to be included in the program’s Selected Acquisition 

Report dated December 31, 2006, expected to be delivered to the Congress

in April 2007. Because the new official cost estimate for the JSF program 

will not be available until after this report is issued we are unable to make 

informed judgments on those estimated costs. It should be noted that after 

our 2006 report was issued on March 15, 2006, DOD released its December 

2005 Selected Acquisition Report, which showed an increase of over $19 

billion in total estimated JSF program costs. 

We identified changes in the program’s cost, schedule, and performance 

since the program rebaseline and analyzed relevant information to 

determine the primary causes of those changes. We reviewed JSF 

management reports, acquisition plans, test plans, risk assessments, cost 

reports, independent program assessments, and program status briefings. 

We interviewed officials from the DOD acquisition program management 

office and prime contractor to gain their perspectives on the performance 

of the program. 

To identify the challenges the program will face in the future, we 

compared the programs plans and results to date with future plans to 

complete development. We analyzed design and manufacturing data from 

the program office and the prime contractor to evaluate performance and 

trends. We reviewed program risk reports, earned value management data, 

and manufacturing data to identify uncertainties and risks to completing 

the program within the new targets established by the program rebaseline. 

We analyzed test program and software data to understand the readiness 

and availability of development aircraft for the test program. We also 

obtained information on past DOD programs from Selected Acquisition 

Reports and prior work conducted by GAO over the past two decades. We

interviewed officials and reviewed reports from several DOD independent

oversight organizations to gain their perspectives on risk in the program. 

To assess the likely impacts of concurrently developing and manufacturing

JSF aircraft we compared the program’s plans and results to date against 

best practice standards for applying knowledge to support major program 

investment decisions. The best practice standards are based on a GAO 

body of work that encompasses 10 years and visits to over 25 major 

Page 26 GAO-07-360 Joint Strike Fighter
Appendix I: Scope and Methodology 

commercial companies. Our work has shown that valuable lessons can be 

learned from the commercial sector and can be applied to the 

development of weapons systems. We identified gaps in product 

knowledge at the production decision, reasons for these gaps, and the 

risks to the program. We also examined the F-22A program’s acquisition 

approach. We interviewed officials from the DOD acquisition program 

management office and prime contractor to gain their perspectives on 

program risks and their approaches to managing risks. 

In performing our work, we obtained information and interviewed officials 

from the JSF Joint Program Office, Arlington, Virginia; F-22A Program 

Office, Wright-Patterson Air Force Base, Ohio; Lockheed Martin 

Aeronautics, Fort Worth, Texas; Defense Contract Management Agency, 

Fort Worth, Texas; and offices of the Director, Operational Test and 

Evaluation, and Acquisition, Technology and Logistics, Program Analysis 

and Evaluation-Cost Analysis Improvement Group, which are part of the 

Office of Secretary of Defense in Washington, D.C. We performed our 

work from June of 2006 to March of 2007 in accordance with generally

accepted government auditing standards. 

Page 27 GAO-07-360 Joint Strike Fighter
Appendix II: Comments from the Department Appendix II: Comments from the Department of Defense 

of Defense 

Page 28 GAO-07-360 Joint Strike Fighter
Appendix II: Comments from the Department 

of Defense 

Page 29 GAO-07-360 Joint Strike Fighter
Appendix II: Comments from the Department 

of Defense 

Page 30 GAO-07-360 Joint Strike Fighter (120570) 
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