Federal Aviation Administration (FAA) Next Generation Air Transportation System
Lead Author: Brian White
This article describes a massive undertaking to modernize the air traffic management enterprise. The topic may be of particular interest to those involved in air transportation whether in connection with their careers or as pilots or passengers on airplanes. For addition information, refer to the closely related topics of Enabling Businesses and Enterprises and Enterprise Systems Engineering.
This case study presents the systems engineering and enterprise systems engineering (ese) efforts in the Next Generation (NextGen) Air Transportation Systems by the Federal Aviation Administration (FAA 2008). NextGen is an unprecedented effort by multiple U.S. federal organizations to transform the U.S. air transportation infrastructure from a fragmented ground-based navigation system to a net-centric satellite-based navigation system. This project is unique to the FAA because of its large scale, the huge number of stakeholder(s) involved, the properties of the system of interest, and the revolutionary changes required in the U.S. Air Transportation Network (U.S. ATN) enterprise.
A sociotechnical system like the U.S. ATN is a “large-scale [system] in which humans and technical constituents are interacting, adapting, learning, and coevolving. In [such] systems technical constraints and social and behavioral complexity are of essential essence”. (Darabi and Mansouri 2014). Therefore, in order to understand changes in the U.S. ATN it was seen as necessary to view it through a lens of evolutionary adaptation rather than rigid systems design. The U.S. ATN serves both military and commercial aircraft with its 19,782 airports, including 547 are commercial airports. Nineteen major airlines, with more than a billion dollars in annual total revenue, along with other 57 national and regional airlines, transport 793 million passengers and realize 53 billion revenue ton-miles.
The Air Traffic Organization (ATO) is responsible for ensuring aircraft navigation in the U.S. National Air Space (NAS) system using a five-layer architecture. Each aircraft goes through different layers and possibly various zones of this architecture as it takes off from an airport until its lands at another airport (Donohue and Zellweger 2001). However, this architecture is fragmented and many issues are raised: an airplane’s path through its route is not optimized, and the path may change its direction from one zone to another, the destination airport’s capacity is limited by the current regulations of minimum aircraft separation distance due to navigation limitations, the real-time weather information is not integrated into the system, and communications are mainly voice-based, etc.
In NextGen major changes to the U.S. ATN design are planned. As already stated, the navigation system will be changed from ground-based communication to satellite-based navigation. The current fragmented architecture will be integrated into a seamless net-centric information system in which the digital communication will replace the current voice communications. Moreover, weather information will be assimilated into decision making and planning across the system.
The FAA’s purpose is “to provide the safest, most efficient aerospace system in the world”. Toward this end the NextGen project is aimed at enhancing the U.S.’s leadership position in air transportation.
During the last three decades the demand for air transportation shows exponential growth. In just one decade from 1995 to 2005 this demand showed a 44% percent increase. Therefore, the change in infrastructure was inevitable. Moreover, 9/11 attacks on the U.S. ATN emphasized this need for change. The combination of a requirement for a safer and more secure network and increasing demand was the motivation for President Bush to enact the Vision 100-Century of Aviation Reauthorization Act on 2003. A major part of this Act was to revolutionize the U.S. ATN by means of the NextGen project. The first integration plan of the project was released in 2004, and the project is estimated to continue until 2025.
The demand behavior of the U.S. ATN shows diverse degrees of congestion among airports. Although there are multitudes of airports in the system, the top 35 most congested airports carried more than 60% of the total traffic consistently during the period of 2000 to 2008. Because the growth of the network demand is not proportional, the demand in congested airports will be even higher.
A study by the Joint Planning and Development Office (JPDO) shows that flight delays in the current network will cause $6.5 billion of economic loss until 2015, and $19.6 billion until 2025. By implementing NextGen the delays are estimated to be reduced by 38% until 2020. Moreover, aircraft CO2 emissions are a major part of environmental pollution in crowded cities; these will be reduced by 14 million metric tons by 2020. The current level of jet fuel usage is also a known problem because of increasing fuel prices. The NextGen project will improve fuel usage by 1.4 billion gallons cumulative through 2020.
NextGen is pursuing multiple goals to retain the U.S. leadership in aviation, to expand the U.S. ATN capacity, to continue to ensure safety, to increase environment protection, to help ensure national air defense, all generally helping to increase the nation’s security (JPDO 2007a).
Eight general capabilities are defined in conducting this mission: (1) network-enabled information access, (2) performance-based operations and services, (3) weather assimilated into decision making, (4) layered adaptive security, (5) positioning, navigation, and timing (PNT) services, (6) aircraft trajectory-based operations (TBO), (7) equivalent visual operations (EVO), and (8) super-density arrival/departure operations.
To create the desired capabilities, general areas of transformations are defined as air traffic management operations, airport operations and infrastructure services, net-centric infrastructure services, shared situational awareness services, layered and adaptive security services, environmental management services, safety management services, and performance management services. The detailed changes in each area are discussed in Concept of Operations for NextGen (JPDO 2007a).
An instructive part of this case study is observing evolution in understanding challenges from initial steps of the project through current efforts for delivering it. As an overall conclusion, the perspective on challenges shifted from technical problems and intra-organizational issues to more enterprise-wide issues.
The NextGen Implementation Plan 2008 discussed the following challenges (FAA 2008):
- performance analysis, to understand and assess operational capabilities
- policy, to balance responsibility between humans and automation, for environmental management processes, and for global harmonization strategies
- acquisition workforce staffing
- environmental planning, to resolve conflicts with local environmental constraints
- transition from current ground-based navigation to automatic dependent surveillance – broadcast (ADS-B) technology.
A more recent report on Targeted NextGen Capabilities for 2025 (JPDO 2011) highlights the effect of the multi-stakeholder nature of the project on raising additional challenges. Achieving Interagency Collaboration is the first issue, which is important in implementing security, safety, policy making, and technological advancement.
Increasing capacity, reducing delay and protecting the environment are the main three promises of the NextGen project. However, reaching the defined high standards is not an easy task. A major part of this challenge is integrating new technologies into legacy systems, aircraft, airports, facilities, and organizations. Airlines and general aviation pilots resist the expense of additional avionics and communications equipment, even though it bolsters the common good of air travel.
Maintaining airports and airspace security requires coherent and harmonious work of multiple U.S. agencies. The core of this challenge is not just changing the technology but also the processes, organizational structures, and enterprises to meet the new requirements of security.
Moreover, the need for greater information sharing in this net-centric environment is a challenge. The current culture of limited information sharing in which inter-organizational and intra-organizational information is strictly divided creates tension in a seamless information sharing infrastructure. In addition to that, the responsibility of generating, sharing, and utilizing useful information should be addressed in advance to avoid costly mistakes.
Verification and validation of NextGen deliverables is a major issue. The traditional systems engineering methods of verification and validation are tailored for testing an isolated system, while by definition a project like NextGen requires new methodologies of verification and validation beyond the scope of one system. The knowledge and experience of advancement in systems engineering in this area can be of priceless value for future projects.
Balance between human decision-making and automation is required to ensure a correct policy for increasing traffic and safety concerns. Changes in both human resource and technological facilities are required to effectively address this challenge.
The support of local communities is essential to facilitate development of the U.S. ATN and its physical infrastructure.
Communication, navigation, and surveillance systems in NextGen are going through major changes in terms of capacity and technology. However, planning required backups for them in case of any emergency is an area of challenge in developing NextGen.
The rise of Unmanned Aircraft Systems (UASs) provides significant opportunities for both military and commercial applications. However, integrating them into the NAS and developing policing and strategies for safe and secure use is a concern for the revolutionized U.S. ATN.
And finally realizing the benefits of NextGen is dependent on the critical mass of early adopters, similar to any technological advancement. Therefore, the NextGen project authority requires well-defined policies for motivating stakeholders’ participation.
Systems Engineering Practices
The FAA NextGen is not just a revolution of the U.S. air transportation infrastructure, but also a shift in its enterprise. The enterprise architecture document, which is developed by JPDO, provides an overview of the desired capabilities (JPDO 2007b).
The enterprise architecture is described using Department of Defense Architecture Framework (DoDAF) and the Federal Enterprise Architecture (FEA). DoDAF is used to describe the operational aspects of the project. The three views of DoDAF, the Operational View (OV), the Systems View (SV), and the Technical Standards View (TV), are presented in the enterprise architecture document. The Overview and Summary Information (AV-1) is the formal statement about how to use the architecture, the Integrated Dictionary (AV-2) defines the terms in the document, the Community Model (OV-1) presents a high level depiction of the NextGen community, the Operational Node Connectivity Description (OV-2) presents the information flow among operational nodes in the system, Operational Information Exchange Matrix (OV-3) details the description of information flow in OV-2. Other architectural views of the system based on DoDAF are the Activity Model (OV-5) which documents activities (functions and processes), the Operational Event/Trace Description (OV-6c) is a part of sequence and timing description of activities, the System Functionality Description (SV-4) explains system functional hierarchies, and the Operational Activity to System Functionality Traceability Matrix (SV-5) is specification of relationships between operational activities in architecture and functional activities. However, a challenging part of applying this Enterprise Architecture is transformation from legacy systems to the new NextGen. This transformation is the ultimate test for relevance and comprehensiveness of the developed Enterprise Architecture.
Acquisition is the heart of systems engineering activities in the FAA NextGen project. As mentioned in Challenges above, the current practice of verification of validation in systems engineering (SE) is geared toward single isolated systems, rather than a myriad of interconnected system of systems (sos). Moreover, the capabilities of NextGen are interdependent, and different programs rely on each other to deliver the promises. 250 unique and highly interconnected acquisition programs are identified in the FAA’s Capital Investment Plan, and these are to be delivered by 1820 FAA acquisition professionals. In addition, program complexity, budget uncertainty, and the challenge of finding acquisition professionals present other problems. The experience of systems acquisition in NextGen can provide a useful knowledge for future similar projects.
Although major portions of the FAA NextGen project are technical transformations and physical infrastructure developments, the transformation in the aviation enterprise is important but to some degree neglected. Part of the issue might be the fact that this transformation is beyond the responsibility and capability of FAA. However, to accomplish NextGen’s perceived benefits it is important to realize the effects of legacy systems, and most importantly the legacy enterprise architecture of the U.S. ATN. Many of the actual challenges in the system arose because of this inattention.
The sequestration in the U.S. government, the Budget Control Act of 2011, has cut the project funding substantially in recent years. As a result the project schedule and portfolio are subject to constant and wide-spread changes. The FAA was focused on delivering Optimization of Airspace and Procedures in the Metroplex (OPAM) program which is designed to reduce the delay, fuel consumption, and exhaust emission in busiest airports. The three areas of Houston, North Texas, and Washington D.C. were planned to complete the design phase on 2013 and start implementation.
Out of 700 planned ADS-B ground stations, 445 were operational on February 2013. ADS-B capability is a NextGen descendant of current radar systems and provides situational awareness for the players in the NAS using the Global Positioning System (GPS) and Wide Area Augmentation System (WAAS).
On the enterprise part of the project, the FAA Modernization and Reform Act of 2012 provided financial incentives for airlines and commercial aviation manufacturers to implement the required equipment in their aircraft. These incentives are designed to engage the air transportation community in the project and to create the critical mass of equipped airplanes.
There are considerable practices in applying NextGen. Establishment of the JPDO made the efforts of the project more coherent and integrated. JPDO’s main responsibility is to coordinate development of NextGen. The role of this organization is to represent multiple stakeholders of the project, which enables it to resolve possible conflicts of interests inside one entity. Moreover, such an organization provides a venue for technical knowledge-sharing, creating a consensus, and making an integrated system.
Emphasizing delivery of the mid-term objectives of NextGen is another lesson of the project. It was a well-known practice documented by Forman and Maier to establish mid-points for complex projects (Forman 2000). Developing a mid-level system provides the system designers an opportunity to examine their underlying assumptions, to identify best practices and heuristics in the context of the project, and to reapply the acquired knowledge thorough evolutionary developments. A major shift in the policy of FAA in recent years was to focus on delivering project mid-term objectives.
There are unique characteristics of NextGen which makes it a valuable case for learning and replicating to other complex transformation projects of sociotechnical systems. The scale of the project for infrastructure transformation is unprecedented. The system includes legacy systems and cutting edge technology, and its performance is based on their coherent work. The project implementation is dependent on involved participation of multiple governmental and commercial organizations. Moreover, this case-study provides a great investigation in enterprise governance and enterprise transformation beyond a single organization.
Darabi, H.R., and M. Mansouri. 2014. "NextGen: Enterprise Transformation of the United States Air Transport Network," in Case Studies in System of Systems, Enterprise Systems, and Complex Systems Engineering, edited by A. Gorod et al. Boca Raton, FL, USA: CRC Press, Taylor & Francis Group.
Donohue, G.L., and A.G. Zellweger. 2001. "Air Transportation Systems Engineering." American Institute of Aeronautics and Astronautics. 193 (1).
FAA. 2008. FAA's NextGen Implementation Plan. Federal Aviation Administration. Washington, DC, USA. Accessed March 29, 2014. Available: http://www.faa.gov/nextgen/media/ng2008_implementation_plan.pdf.
Forman, B. 2000. "The political process and systems architecting," in The Art of Systems Architecting, 2nd ed., edited by M.W. Maier and E. Rechtin. Boca Raton, FL, USA: CRC Press LLC.
JPDO. 2007a. Concept of operations for the next generation air transportation system. Joint Planning Development Office. Accessed March 29, 2014. Available: http://www.jpdo.gov/library/nextgen_v2.0.pdf.
JPDO. 2007b. Enterprise Architecture V2.0 for the Next Generation Air Transportation System. Joint Planning and Development Office. Accessed March 29, 2014. Available: http://www.jpdo.gov/library/EnterpriseArchitectureV2.zip.
JPDO. 2011. Targeted NextGen Capabilities for 2025. Joint Planning and Development Office. Accessed March 29, 2014. Available: http://www.jpdo.gov/library/2011_Targeted_NextGen-Capabilities_for_2025_v3.25.pdf.
Darabi, H.R. and M. Mansouri. 2014. "NextGen: Enterprise Transformation of the United States Air Transport Network." Case Studies in System of Systems, Enterprise Systems, and Complex Systems Engineering. Gorod, A., B.E. White, V. Ireland, S. J. Gandhi, and B.J. Sauser. Boca Raton, FL: CRC Press, Taylor & Francis Group. Scheduled for publication in July 2014. http://www.taylorandfrancis.com/books/details/9781466502390/. Accessed 29 March 2014.