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Case Study Examples (1/22) – SoS Example: (Abridged) Outline
Background Purpose History Transformation Needed and Why System of Systems Environment Scope Structure Boundaries Internal Relationships External Factors Constraints Constituents Sponsor(s) Customer(s) Governing Body(ies) Other Stakeholders Challenges Development Project/Program Management Systems Engineering Results Transformation Accomplished Final System Description Analysis Lessons Learned Best Practices Summary Conclusion(s) Refer to (Gorod, et al. Chapter 3) for much more detailed case study outline. 2/23/2019
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Case Study Examples (2/22) – Air Traffic Management: Air/Ground Radios (1/14)
Background The Center for Advanced Aviation Systems Development (CAASD), located in McLean, VA, of The MITRE Corporation (MITRE) supports the Federal Aviation Administration (FAA) as a Federally Funded Research and Development Center (FFRDC), a non-profit entity operating in the public interest that supports only government agencies. In the mid- to late- 1990s, CAASD asked staff members of MITRE’s Air Force Center (AFC) located in Bedford, MA, to provide technical support to improve air traffic control (ATC) air-ground communications. The principal motivation for involving Bedford was the potential for leveraging its laboratory facilities in experiments and simulations. Happily, there was considerable technical analysis expertise on hand as well, e.g., in Digital communications Analog radios Software engineering Automation systems 2/23/2019
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Case Study Examples (3/22) – Air Traffic Management: Air/Ground Radios (2/14)
Purpose The main objective was to improve communications spectrum utilization in the upper 19 MHz-wide portion of the ATC Very High Frequency (VHF) band, MHz, consisting of kHz channels. Situation to improve: Push-to-talk (PTT) (where only one party can speak at one time) pilot-controller communications was conducted using analog voice radios. Only one conversation could be accommodated within each 25 kHz channel. Each commercial airliner was equipped with two such radios for safety. The initial goal was to achieve at least an order of magnitude improvement in spectrum efficiency by Inventing a new digital waveform. Packing in at least 10 PTT conversations in every 25 kHz channel. All without undue inter-channel and co-channel interference. Radios doing voice and/or data to minimize the number of radios required on-board aircraft, particularly commercial airliners. 2/23/2019
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Case Study Examples (4/22) – Air Traffic Management: Air/Ground Radios (3/14)
History Air traffic management technology was decades old and woefully outdated. The state-of-the-art of digital communications was Well-advanced Highly reliable Mature Very flexible Amenable to creative designs. Transformation Needed and Why Burgeoning aircraft traffic demanded more communications capacity. There were fears of running out of communications spectrum. A capacity crisis developing in 5-10 years was predicted. 2/23/2019
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Case Study Examples (5/22) – Air Traffic Management: Air/Ground Radios (4/14)
System of Systems (1/5) Environment Many existing systems populate the airspace, including Aeronautical Operational Control (AOC), Air Traffic Services (ATS), and airport, airbase, and ATC ground facilities. Manufacturers of aircraft, communication and radar equipment, navigation aids, safety systems, etc., are among the contributors. Airliners, business jets, and other civil aircraft, gliders, drones, General Aviation (GA) (which includes the military) are all part of the aircraft mix. The flying public, aircraft pilots, crews, and current passengers can be included. Scope (1/2) Rules/Regulations Airlines: pilot and crew training; instrument flight rules; required equipage; baggage handling; flight planning; gate management; taxiways; takeoffs; en route waypoints; altitude, separation, and special use airspace restrictions; flow control; re-routing; holding patterns; runway management; landings; etc. General aviation: pilot training; visual flight rules; required equipage; altitude, separation, and special use airspace restrictions; etc. Safety: weather; flight plans; aircraft and equipment maintenance; boarding security; passenger behavior; aircraft separation (horizontal and vertical); primary and secondary radar surveillance; collision avoidance systems; etc. 2/23/2019
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Case Study Examples (6/22) – Air Traffic Management: Air/Ground Radios (5/14)
System of Systems (2/5) Scope (2/2) Standards Voice/Data communications Mode S (see below) Traffic Collision Avoidance System (TCAS) Automatic Dependent Surveillance - Broadcast (ADS – B) Etc. Manufacturing Aircraft Radars Primary Secondary: ATC Radar Beacon System (ATCRBS), Mode S, etc. Radios Analog voice double sideband amplitude modulation (DSB-AM) Aircraft Communications Addressing and Reporting System (ACARS) (for data; operated by ARINC) Navigation aids Global Positioning System (GPS), Global Navigation Satellite System (GNSS) GLONASS (aka Global Orbiting Navigation Satellite System; Russia), et al. Inertial Navigation System (INS) VHF Omnidirectional Range (VOR) equipment LOng RAnge Navigation (LORAN) equipment Simulators 2/23/2019
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Case Study Examples (7/22) – Air Traffic Management: Air/Ground Radios (6/14)
System of Systems (3/5) Structure Civil Aviation Authorities (CAAs) (in foreign countries) and the FAA (in the U.S. which represents both civil and military aviation) form the International Civil Aviation Organization (ICAO) which regulate all aspects of aviation with safety as the top priority. EUROCONTROL: European Organisation for the Safety of Air Navigation Other Agencies: e.g., RTCA (used to be Radio Technical Commission for Aeronautics) Aeronautical Radio, Inc. (ARINC) (supporter of airlines). Various other organizations are also involved, e.g., National Business Aviation Association (NBAA) Airlines Electronic Engineering Committee (AEEC) Air Line Pilots Association (ALPA) Aircraft Owners and Pilots Association (AOPA) International Council of Aircraft Owner and Pilot Associations (IAOPA). Boundaries (1/2) Worldwide operation Earth’s Surface Atmosphere. 2/23/2019
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Case Study Examples (8/22) – Air Traffic Management: Air/Ground Radios (7/14)
System of Systems (4/5) Boundaries (2/2) Air/Ground radios focus Pilot/Controller communication Voice Data Equipage Airliners Ground sites. Internal Relationships The MITRE Corporation The (then) Air Force Center (AFC) Center for Advanced Aviation Systems Development (CAASD). RTCA Special Committee (SC) 172 – Future Air-Ground Communications in the VHF Aeronautical Band (118 – 137 MHz) “teams” MITRE-FAA-NBAA ARINC-Airlines-AEEC-Boeing. ICAO Working Groups B (safety, etc.) C (radios, etc.). 2/23/2019
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Case Study Examples (9/22) – Air Traffic Management: Air/Ground Radios (8/14)
System of Systems (5/5) External Factors Existing SoS included DSB-AM radios ACARS Etc. European short-term solution of 8.33 kHz channel spacing which Required modification of DSB-AM radios with Narrower signal spectrum Improved frequency stability. FAA’s lack of investment in ground radios. Airlines’ reluctance to buy more airborne radios. Constraints Interference specifications Co-channel (proved more difficult) Adjacent channel. Existing frequency assignments. 2/23/2019
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Case Study Examples (10/22) – Air Traffic Management: Air/Ground Radios (9/14)
Constituents Sponsor(s) FAA Next-Generation Air-Ground Communications System (NEXCOM) CAASD (of MITRE Air Force Center’s effort) Customer(s) CAASD (of AFC’s effort) RTCA SC 172 ICAO – Aeronautical Mobile Communications Panel (AMCP) Working Groups B C Airlines. Governing Bodies RTCA ICAO. Other Stakeholders Air Traffic Controllers Union ARINC EUROCONTROL. 2/23/2019
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Case Study Examples (11/22) – Air Traffic Management: Air/Ground Radios (10/14)
Challenges Postulating various digital communication alternatives Analyzing candidate modulation/coding schemes Reaching consensus within RTCA SC 172 Recommending higher capacity waveform Establishing ICAO standard. Development (1/2) Project/Program Management FAA managed CAASD program fairly closely CAASD managed AFC project quite loosely AFC project leader (PL) (yours truly) Traveled frequently to CAASD Coordinated often with CAASD PL. 2/23/2019
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Case Study Examples (12/22) – Air Traffic Management: Air/Ground Radios (11/14)
Development (2/2) Systems Engineering (nearly all technical work was performed by AFC) Analyzed many candidate modulation/coding schemes, e.g., D8PSK 8LFM 16QAM/4QAM Etc. Investigated interference (concerning both new and existing radios) Ambient/Channel noise Adjacent channel Co-channel Co-site. Devised Time Division Multiple Access (TDMA) scheme 25 kHz channel width 31.5 kb/s peak data rate (accommodating link management and other overhead) 4 time slots in 30 msec frame Either voice or data in each time slot frame at 4.8 kb/s data rate. Experimented with acceptable time delays. In laboratory With live demonstrations. Assessed radio State-of-art Cost. TDMA Frame 120 msec Management Sub-Channel Voice or Data Time Slot 30 msec A B C D 2/23/2019
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Case Study Examples (13/22) – Air Traffic Management: Air/Ground Radios (12/14)
Results Transformation Accomplished Recommended D8PSK and TDMA (see preceding chart) Achieved consensus agreement in RTCA SC 172 Proposed same waveform to AMCP VHF Digital Link (VDL) Mode 2 (data only) (to replace ACARS) 3 (voice and data) (to replace analog DSB-AM and 8.33 kHz radios) Achieved consensus in AMCP WGs B and C. Final System Description VDL Modes 2 and 3 became ICAO standards. Made progress on implementation VDL Mode 2 got implemented Still awaiting implementation of VDL Mode 3. Analysis Published much technical work Showing tradeoffs Justifying results. Despite much sound analytical work, the airline segment Claimed co-channel protection was insufficient. Complained about the cost of on-board radio replacements. 2/23/2019
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Case Study Examples (14/22) – Air Traffic Management: Air/Ground Radios (13/14)
Lessons Learned Greater attention should have been devoted to International need for simple “drop-in” radio replacements without Need for short-term and extensive radio replacements. Any degradation to existing performance with extant radios. Undue cost increases. Airlines needs for More protection against co-channel interference. Lower cost on-board radios. Difficulties associated with smooth/timely transitions to new systems. Potential concerns of air traffic controllers. Bureaucratic process was Formidable, in both U.S. Europe. Exacting Every issue was addressed. Non-technical considerations dominated. Slow; there Were many meetings. Was extensive coordination. Stakeholder opinions/needs mattered Greatly. Often more than technical issues. 2/23/2019
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Case Study Examples (15/22) – Air Traffic Management: Air/Ground Radios (14/14)
Best Practices Coordination needs to be Open Frequent Technical Managerial. Personal relationships involving Friendliness Trust Competence matter. Summary efforts on new digital waveform gained significant traction (AMCP 1994) (ICAO 1996) (CIWG 1999). National/International efforts were highly satisfying professionally. Conclusion Similar efforts on NextGen would be welcome. 2/23/2019
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Case Study Examples (16/22) – Air Traffic Management: CASE (1/7)
Next the original version Complex Adaptive Systems Engineering (CASE) methodology is applied to air traffic management examples (White 2008a). 2/23/2019
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Case Study Examples (17/22) – Air Traffic Management: CASE (2/7)
Activity 1: Create Climate for Change As just described, in the mid-1990s, The MITRE Corporation, in operating one of its FFRDCs – the Center for Advanced Aviation Systems Development (CAASD) that supports the Federal Aviation Administration (FAA) – was involved in an approximately four-years effort to modernize air traffic control (ATC) air-ground communications between pilots and controllers. A healthy climate for change was already established by the even-then recognized need to provide more capacity in the 25 kHz-wide channels allocated to ATC communication. Air traffic at major airports was expected to increase, and existing communications capacity was predicted to be exhausted within about 7 years around several metropolitan areas, especially New York City. Thus readiness to change was driven by an impending threat. The ensuing RTCA (formerly known as the Radio Technical Commission for Aeronautics) and International Civil Aviation Authority (ICAO) meetings became self-organizing venues. In quadrupling the communications capacity we collaborated and shared many experiences and learnings in creating a widely acceptable digital waveform. Along the way we thoroughly explored innovation and integration options while considering inter-channel, co-channel, and aircraft co-site radio interference tradeoffs, for example. 2/23/2019
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Case Study Examples (18/22) – Air Traffic Management: CASE (3/7)
Activity 2: Architect a Strategy Consider trying to improve the air transportation system in just one component, say, the communications system between pilots and air traffic controllers. The aforementioned attempt in the 1990s to introduce a fully-digital, integrated voice-data radio capability had only limited success because the system boundary was not inclusive enough. An ICAO waveform standard was achieved (ICAO 1996), but the entire system (VDL Mode 3) was not implemented because of inadequate support. Air traffic controllers were reluctant to modify existing procedures. The European ATC association (EUROCONTROL) wanted another round of analog channel splitting. The airlines balked at yet another new radio. The FAA was unable to secure congressional funding for the ground radios. Etc. Greater success might have been achieved by engaging more closely with all these stakeholders early – treating them as part of the system. In other words, a better strategy should have been architected – in the beginning of the effort. 2/23/2019
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Case Study Examples (19/22) – Air Traffic Management: CASE (4/7)
Activity 3: Target Outcome Spaces In contrast, technology is not the limiting factor in modernizing air transportation in the United States. For instance, the Air-ground communications VDL Mode 3 radios (of the previously mentioned ICAO standard), and In-cockpit situational awareness, Automatic Dependent Surveillance - Broadcast (ADS-B) systems represent mature technologies. Other problems involving people, processes, and business tradeoffs have thus far prevented the widespread introduction of these subsystems into the air traffic management system. Outcome spaces need to include these entities! Activity 4: Reward Results An especially difficult case would be trying to visualize how Reward Results would work for all stakeholders in ATC and air traffic management. Now may be the time to experiment in limited ways under the current NextGen effort. A start might be with some applied research involving two groups of stakeholders. 2/23/2019
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Case Study Examples (20/22) – Air Traffic Management: CASE (5/7)
Activity 5: Formulate Decision-Making Heuristics Americans used to wonder whether yesterday’s pervasive airline delays and largely nonexistent airline profits could have been mitigated by taking earlier action on modernizing the ATC system in U.S. It’s curious that dire predictions of running out of airport capacity within seven years or so were still being made in 2008 just as emphatically as 10–15 years before that! We wondered whether this was “crying wolf” again, thus resulting in less motivation to continue pushing for modernization. Happily for the airlines, they seem to have fixed their profit situation without our help, at least, by increasing ticket prices and charging for food on-board, and imposing heavy baggage, rebooking, and cancellation fees. Or, perhaps it is time to wait no longer and to think about transforming air transportation in the United States safely rather than focusing so much on effectiveness and efficiency. For example, greater emphasis on sharing military and civilian air traffic management resources (e.g., air traffic controllers and funding) and assets (e.g., air bases, airports, and aircraft) might lead to a larger outcome space of creative solutions benefitting multiple stakeholders. Some much better “rules-of-thumb” are needed for decision takers in this domain! 2/23/2019
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Case Study Examples (21/22) – Air Traffic Management: CASE (6/7)
Activity 6: Stimulate Natural Processes An example of Activity 6 is the experimentation with Automatic Dependent Surveillance – Broadcast (ADS-B) using MITRE’s Universal Access Transceiver (UAT) (RTCA 282a 2004) during, e.g., the Capstone project, in the challenging (because of prevailing bad weather and rugged terrain) air traffic environment of general aviation (GA) users in Alaska. (Peed 2009)* What better environment (where there have been many small aircraft crashes) might be used to demonstrate the value of ADS-B for improving safety? The FAA successfully created worldwide interest through this competing system concept, instigated in part by providing free radio equipment to GA users. (Peed 2009)* Thus MITRE’s compelling experiment really stimulated renewed worldwide attention toward implementing ADS-B! __________ * This 171-page briefing document (which is in the public domain) is a very comprehensive treatment that very well demonstrates the complexities of the air traffic management surveillance domain. 2/23/2019
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Case Study Examples (22/22) – Air Traffic Management: CASE (7/7)
Activity 7: Develop in Operational Environs Although the CAASD-invented User Request Evaluation Tool (URET) was conceived in the laboratory, it matured in the field; it was used in the Indianapolis and Memphis Air Route Traffic Control Centers (ARTCCs) from November 1997 through 2008 and has since been installed nationwide. URET enhances the ability of air traffic controllers to foresee potential aircraft conflicts many minutes in advance. This allows enough time for pilots to take corrective action without significantly disrupting flight times or sacrificing passenger comfort. Activity 8: Assess. Learn, and Re-Plan NextGen is an example of learning from past efforts in the air traffic management arena. In a larger context the FAA joined with several other government agencies under the Joint Planning and Development Office (JPDO) to modernize air transportation in the United States. 2/23/2019
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Takeaways Objectives were established, to Show how practice drives theory. Advocate a workable methodology. Apply Complex Adaptive Systems Engineering (CASE) to SoSE. A fairly detailed CASE methodology was offered. This was updated from the initial 2008 version. The number of activities elucidated increased from 8 to 23. It was explicitly suggested how CASE can be applied to SoSE. SoS and/or SoSE was cited in each CASE methodology chart. Air traffic management case study examples were provided, viz., Air/Ground communication between pilots and controllers with new, more effective and spectrally efficient digital waveform. How the original CASE methodology applied in this arena. The Again, let’s now hear some of your comments on this course to date. 2/23/2019
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Syllabus (tentative) 2/23/2019 24
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Reminders (due 7 Mar) Case Study Track Weekly Homework Track
Select, Analyze, (Re)Engineer, and Document Your CS Case Study Weekly Homework Track Discussion Board 7 (one post and one response) Problem 1 (see Chart 20 of Session 7) Provide story of humility in dealing with complex problems. Problem 2 (see Chart 37 of Session 7) Provide story of courage in dealing with stakeholders (without naming names) Quiz 7 re: Extremely complex World problem Select/Specify such a problem that has not yet been mentioned. What organization might be able to make progress on this, and why? What three ideas from the complexity literature resonate with you the most, and why? 2/23/2019
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No Assignment for 14 March Session 9
Work on Your Case Study Capstone Report and Presentation for 21 March Session 10 Synchronous Session 10 to be arranged Participate in 14 Session 9 facilitation on the latest in architecture frameworks Synchronous Session 9 to be arranged 2/23/2019
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