DOD has been successfully using unmanned air vehicles such as the Global Hawk and Predator to gather intelligence and perform surveillance and reconnaissance missions for military purposes. Beginning in the mid-1990s, DOD began to conceive of a different type of unmanned air vehicle—the unmanned combat air vehicle or UCAV—which would be capable of performing dangerous, lethal combat missions, including suppression of enemy air defenses (SEAD). Unlike other unmanned air vehicles, UCAVs would carry weapons as well as electronic jammers to confuse enemy radars. DOD also envisioned that the air vehicle would operate more autonomously than other unmanned air vehicles, requiring little or no human input from ground stations to complete their missions or change flight paths. In addition, UCAVs would be stealthy and capable of flying in groups or with manned aircraft. The potential of these weapons has garnered high interest from both Congress and DOD. In the fiscal year 2001 Defense Authorization Act, Congress set a goal that by 2010, one-third of DOD’s deep strike force be unmanned in order to perform this dangerous mission. In addition to the potential for saving lives on risky missions, the UCAV could provide mission capability at less cost than manned aircraft. Program officials initially aimed for the UCAV’s acquisition cost to be one-third of the joint strike fighter and operations and support costs to be at least 75 percent lower. Because of the promise of unmanned air vehicles, the Office of Secretary of Defense has established a joint-service unmanned air vehicles task force to help promote the development and fielding of these systems, including making sure that there is multiservice cooperation. This task force is responsible for outlining the future of DOD’s unmanned air vehicles. In the late 1990s, DARPA and the Air Force began pre-acquisition efforts to conduct advanced technology demonstrations to show the technical feasibility of using UCAVs to penetrate deeply into enemy territory to attack enemy targets. Boeing Corporation was selected in 1999 to develop and demonstrate two demonstrator UCAVs—designated X-45A. (See fig. 1.) The DARPA-Air Force UCAV original plan also called for building and demonstrating two prototypes during the pre-acquisition phase, called X-45B, that are larger and incorporate low observable technology. (See fig. 2.) These air vehicles were expected to be more representative of the operational air vehicle that the Air Force planned to field. Initially, the Air Combat Command, which establishes mission and performance requirements, determined that the X-45B should be focused on performing SEAD missions within the air superiority mission area. This decision was made to address the limited inventory of current assets in the air superiority mission area and to counter the challenges and deficiencies associated with conducting SEAD missions. As of February 2003, 55 of 160 planned demonstrations have been completed. Most of the demonstrations designed to validate the basic flight characteristics of the air vehicle have been completed. Only a small number of the demonstrations needed to validate the ability of a single air vehicle to perform a preemptive destruction mission have been completed. The more demanding demonstrations—those designed to demonstrate technologies and software for highly autonomous, multivehicle operations (with both manned aircraft and unmanned air vehicles), and the more difficult aspects of the SEAD mission against mobile targets—have not begun. The product development decision that DOD is approaching for its UCAV program represents a commitment by the product developer to deliver a product at established cost, schedule, and performance targets and identifies the amount of resources that will be necessary to do so. Our studies of leading companies have shown that when requirements and resources were matched before product development was started, the more likely the development was able to meet performance, cost, and schedule objectives. When this took place later, programs encountered problems such as increased cost, schedule delays, and performance shortfalls. A key to achieving this match is to ensure that the developer has the resources—technology, design and production knowledge, money, and time—needed to design, test, manufacture, and deliver the product. It is not unusual for a customer to initially want a high-performing product that does not cost much or take too long to develop. But such an expectation may exceed the developer’s technology or engineering expertise, or it may be more costly and time-consuming to create than the customer is willing to accept. Therefore, a process of negotiations and trade-offs is usually necessary to match customer requirements and developer resources before firming requirements and committing to product development. Our work has shown that successful programs will not commit to product development until needed technologies are ready to satisfy product requirements. In other words, technology development is separated from product development. If technology is not sufficiently mature at the beginning of a product development program, the program may need to spend more time and money than anticipated to bring the technology to the point to which it can meet the intended product’s performance requirements. Testing is perhaps the main instrument used to gauge technology maturity. Testing new technologies before they enter into a product development program, as DOD is doing now by demonstrating the two X-45A demonstrators, enables organizations to discover and correct problems before a considerable investment is made in the program. By contrast, problems found late in development may require more time, money, and effort to fix because they may require more extensive retrofitting and redesign as well as retesting. These problems are further exacerbated when the product development schedule requires a number of activities to be done concurrently. The need to address one problem can slow down other work on the weapon system. Figure 3 illustrates the timing of the match between a customer’s requirements and a product developer’s resources for successful and problematic programs we have reviewed. During 2002, significant requirements were added to the UCAV program after the schedule was accelerated by 3 years. This step put the program at considerable risk because it increased the gap between requirements and resources. The program added two new requirements—one for electronic attack capability and one for increased flying range—while reducing a critical resource, time, to mature key UCAV technologies. As a result, the Air Force and DARPA anticipated that most of the 15 key technologies, system attributes, or processes supporting the aircraft’s basic capabilities would move from all low risk to mostly medium risk of achieving desired functionality by the time a product development decision was reached; one would be at high risk. The UCAV program’s original requirements were difficult to meet because they posed significant but manageable technical challenges to building an air vehicle that is, at once, affordable throughout its life cycle, highly survivable, and lethal. In the last year, both air vehicle and mission equipment requirements were increased. The original requirements called for a UCAV that would have a low life-cycle cost, survivable design; a mission control station that can fly single or multiple UCAVs at one time; a secure command, control, and communications network; completely autonomous vehicle operation from takeoff to landing; off-board and on-board sensors with which to locate targets; and human involvement in targeting, weapons delivery, and target damage assessment. Once these requirements were established, the UCAV contractor identified 15 technologies, processes, and system attributes the UCAV would have to possess to meet those requirements. These elements became a way to gauge the level of knowledge (in terms of risk) that the contractors had. Right now, technologies that support some of these capabilities, such as autonomous operation, are not yet mature. We used their risk assessments and criteria for the 15 technologies, processes, and system attributes to determine current system integration risk as well as technology risk. We believe technology readiness levels would have provided a more precise gauge of technology maturity, but program officials did not provide them. Currently, 10 technologies, processes, and system attributes are considered to be medium risk by the Air Force and DARPA. Medium risk means that there is a 30 to 70 percent probability of achieving the desired functionality for the initial operational UCAV. Moreover, 5 are currently considered to be high risk, that is, there is less than 30 percent probability of achieving their functionality. Table 1 provides the current risk level of the 15 UCAV technologies, processes, and system attributes for original UCAV objectives. Originally, the UCAV program was tasked with providing an air vehicle that would perform both preemptive and reactive SEAD missions against fixed and mobile targets that are extremely demanding from both a mission and capability perspective. The reactive mission is more demanding than the preemptive mission because the UCAV will have less time to find and engage mobile targets. When DOD decided to accelerate delivery of the initial UCAVs, the program was relieved of meeting the requirement for reactive SEAD, making for a better balance between requirements and available resources. However, requirements were subsequently added that increased the challenge of matching requirements with resources. These requirements include an electronic attack mission and increased combat range and endurance. Electronic attack: DOD’s electronic attack mission is currently performed by the Navy’s aging EA-6B Prowler aircraft. Electronic attack confuses enemy radars with electronic jammers. In 2001, the Navy conducted an analysis of alternatives for replacing the Prowler. Air Combat Command planners determined that the UCAV could fill portions of this role quickly and added the requirement to the program. As currently structured, the program does not plan to demonstrate electronic attack technologies on UCAV demonstrator or prototype vehicles before product development begins. According to program officials, the biggest additional challenge associated with this change is the integration of existing electronic attack technologies into a low observable air vehicle. Program officials are also concerned that downsizing and repackaging current electronic warfare technology to fit into a smaller space, with sufficient cooling and power, and incorporating antennas and other apertures into the low observable signature of the UCAV may pose additional challenges.