An Air Transportation System-of-Systems Model

An Air Transportation System-of-systems model

An aircraft is but one of multiple systems within an overarching air transportation system-of-systems (ATS) influenced by multiple stakeholders and external political, economic sociological, legal, technological, and environmental scenario factors. Gosh et al, illustrate the ATS using an Atomic Model, which helps to visualize the multiple elements and the complexity of the air transportation system-of-systems. This short note introduces the ATS Atomic Model as developed by Gosh et al. and suggests an enhanced version of the Atomic Model to add stakeholders and clarify the relationships of the stakeholders in what is deemed to be a more holistic model of the ATS.

By Leo Jeoh

Introduction

An aircraft is a complex product comprised of a wide range of cross-interacting sub- systems that together allow it to achieve the common objective of safe and purposeful flight. The sub-systems themselves are individually extremely complex systems (Mowery and Rosenberg, 1981), and the number of such systems in an aircraft has grown from just a handful to hundreds in modern times that have to be integrated together (Becz et al., 2010).

The Atomic Model of an ATS

Adding to the technical complexity, the aircraft is but one of multiple systems within an overarching air transportation system-of-systems (ATS) influenced by multiple stake- holders and external political, economic, sociological, legal, technological, and envi- ronmental scenario factors (Kroll, 2012). In civil aviation, the aircraft is used for a wide range of missions, such as the air transportation of passengers and goods, training, and missions supporting public services and institutions such as emergency medical services, firefighting, and surveillance. Ghosh et al. (Ghosh, Schilling, and Wicke, 2017) illustrate the ATS by using an Atomic Model as shown in Figure 1, which helps to visualize the multiple elements and hence complexity of the air transportation system-of-systems. In their model, the nucleus is composed of the aircraft, surrounded by manufacturers, airlines, airports, and air navigation services providers (ANSPs) as stakeholders, according to a 4-stakeholder model by Weiss et al. (Weiss et al., 2011). Stakeholders in this context are groups or individuals that are directly involved in the design, operation, or technology decisions of the aircraft. They note that the customer, although a key driver of air transportation demand, is not directly involved in such decisions and is hence not depicted as a direct stakeholder. External scenario factors that may influence the ATS or may be influenced by a change in the ATS are depicted as elements orbiting the nucleus. The significance of the size of elements depicted in the Atomic Model is not explained in the paper by the authors, nor is the outer circle that seems to link the orbits of the external scenario factors.

Enhanced Atomic Model of an ATS

A more detailed review of the aviation ecosystem by the Netherlands Aerospace Centre (NAC) (Verstraeten, Roelen, and Speijker, 2016) indicates that there are more stakeholders that should be included in the ATS as shown in Table 1. While most of the differences in terminologies between the Atomic Model and the NAC’s list can be rationalized as a matter of different categorization, regulators and other service providers appear as stakeholders that are not represented and hence should be included in the ATS.

An enhanced version of the Atomic Model with the proposed additions in stake- holders is shown in Figure 2. In this representation of the ATS, airports and air traffic control (ATC) systems have been added to the same level as aircraft, as they should be considered core systems in the ATS. Airports and ATC systems are the principal infrastructure systems for the ATS with airports representing infrastructure that handles the aircraft while on the ground, and ATC systems representing the airside of infrastructure (Teodorovic´ and Janic´, 2017; Odoni, Rousseau, and Wilson, 1994). Additionally, the terms airlines and airports have been replaced by aircraft operators and airport operators, respectively, to clarify the delineation between systems and stakeholders. The outer circle has also been removed, and all elements are sized equally for better clarity in visualization.

References

Becz, Sandor et al. (2010). Design System for Managing Complexity in Aerospace Systems. Conference Paper. DOI: 10.2514/6.2010-9223.
Ghosh, Robin, Thomas Schilling, and Kai Wicke (2017). “Theoretical framework of systems design for the air transportation system including an inherently quantitative philosophy of scenario development”. In: Journal of Air Transport Management 58, pp. 58–67. ISSN: 09696997. DOI: 10.1016/j.jairtraman.2016.09.007.
Kroll, Ehud (2012). “Design theory and conceptual design: contrasting functional decomposition and morphology with parameter analysis”. In: Research in Engineering Design 24.2, pp. 165–183. ISSN: 0934-9839 1435-6066. DOI: 10.1007/s00163-012-0149-6.
Mowery, David C. and Nathan Rosenberg (1981). “Technical change in the commercial aircraft industry, 1925–1975”. In: Technological Forecasting and Social Change 20.4, pp. 347–358. ISSN: 00401625. DOI: 10.1016/0040-1625(81)90065-2.
Odoni, Amedeo R., Jean-Marc Rousseau, and Nigel H. M. Wilson (1994). “Models in urban and air transportation”. In: Operations Research and The Public Sector. Handbooks in Operations Research and Management Science. Chap. 5, pp. 107–150. ISBN: 9780444892041. DOI: 10.1016/s0927-0507(05)80086-6.
Teodorovic´, Dušan and Milan Janic´ (2017). “Transportation Systems”. In: Transportation Engineering, pp. 5–62. ISBN: 9780128038185. DOI: 10.1016/b978-0-12-803818- 5.00002-0.
Verstraeten, J.G., A.L.C. Roelen, and Lennaert Speijker (Jan. 2016). Safety performance indicators for system of organizations in aviation. Report NLR-TP-2016-626. Netherlands Aerospace Centre.
Weiss, Marco et al. (2011). Enhanced Assessment of the Air Transportation System. Conference Paper. DOI: 10.2514/6.2011-6888.