Cover: Complexity Challenges in Cyber Physical Systems by Saurabh Mittal and Andreas Tolk

Complexity Challenges in Cyber Physical Systems

Using Modeling and Simulation (M&S) to Support Intelligence, Adaptation and Autonomy

Saurabh Mittal

The MITRE Corporation
Fairborn
OH, USA

Andreas Tolk

The MITRE Corporation
Hampton
VA, USA







No alt text required.



To the Infinite Intelligence that created things simple, just,
and accommodating enough, which manifests itself in
complex universes, both within and without, that we all
share, enjoy, and strive to understand
.

Saurabh Mittal

To all scientists and researchers who dare to leave the
comfort of their home discipline and seek collaboration with
like‐minded partners to create transdisciplinary teams
inspiring progress in our complex work
.

Andreas Tolk

A signature.

Preface

The various definitions for Cyber Physical Systems (CPSes) all focus on their computational and physical components, integrating sensors, networks, motors, and more. But we often overlook that CPS will significantly change the way we access systems and our environment. They are ubiquitous: cars self‐park, recognize street signs and react accordingly, know the distance to other cars and keep the correct distance, and more. CPS allows a new family of medical devices, from surgical assisting tools to smart prostheses. Smart houses observe the comfort level of people and control the air conditioning accordingly. They are learning when people are home, can prepare their meals and keep the meals warm in case of a traffic jam. If the house were part of the smart city, sensors would have learned about the jam and diverted the traffic, automatically reconfiguring the traffic lights and communicating the news to the smart cars. First responders as well as soldiers are getting accustomed to their colleague CPS in human cyber teams, where the CPS can assess regions too dangerous or otherwise not reachable for the human team partners. However, all this support comes with a price: growing complexity! How can we either manage or govern such intelligent, adaptive, and autonomous systems? How can we take advantage of positive emergence, and avoid the major consequences of negative ones?

We went through a similar dramatic change before, namely when the Internet changed our view on searching for and gaining access to information. Many CPSes are using the Internet to gather and change information as well; and again, it comes with a price. Before the Internet era, many complex systems had both the software and hardware components, but they were shielded from cyberattacks due to a lack of network access. Due to the additional capability of connectedness of these components across varied networks (both within and without the organization that own the CPS), new challenges have emerged. Some of the challenges include cyber security, control, test, degree of connectivity, constant vigilance and operation, degree of autonomy, intelligence‐based behavior, resilience, and impact on the socioeconomic fabric.

As is the case in many current publications, CPS and Internet of Things (IoT) are used interchangeably but there are some subtle differences between the two. We understand CPS as domain‐specific versions of IoT, so the difference lies in terms of scale, societal impact and the propagation of effects. CPS are more focused towards a specific domain such as aviation, health, military, defense, manufacturing, etc. Due to the domain‐specific nature, CPS can be studied in more detail at both the operational technology and information technology levels. However, the resulting danger is that CPS within their domains share neither their insights nor benefit from insights of other CPS from other domains. A domain‐agnostic common theory providing common methods that lead to domain specific solutions would be advantageous, and some candidates exist and will be discussed, but no common formalism in support of this idea has been widely accepted yet.

Modeling and Simulation (M&S) has emerged as a mechanism by which various CPS challenges can be studied in a virtual environment. Model‐based engineering (MBE) and simulation‐based engineering are two distinct activities, even though the simulation activity subsumes the modeling activity. A model is an abstract representation of the system and is evaluated in an environment that may be a live (people using real systems), a virtual (people using simulated systems), or a constructive (simulated people and systems) environment. The simulation infrastructure ensures the model system is provided the right environment for evaluating the capabilities, which are essentially the system's capabilities that need to be tested and evaluated.

We started our journey in Fall 2017, when we gratefully received some internal MITRE research funding to research the challenges of hybrid simulation in support of CPS. We allocated part of the funding to bring experts to a panel discussion. The experts belonged to disparate domains who employ M&S to address the CPS challenges and conduct CPS engineering together. Interestingly, this spawned some collaboration, as we discovered similarities in our challenges and solutions, from which this book ultimately emerged. This book tries to organize the obtained insights and report the latest in the use of M&S for CPS engineering. We address the subject in five parts: Introduction, Modeling Support to CPS Engineering, Simulation‐Based CPS Engineering, The Cyber Element, and The Way Forward.

The Part I begins with a chapter from us and provides an overview of complexities associated with the application of M&S to CPS Engineering. Castro et al. in the second chapter, provide a more detailed description of the challenges in the operation and design of intelligent CPS. The third chapter by Mazal et al. discusses M&S in the context of autonomous systems involvement within the North Atlantic Treaty Organization (NATO). Part II begins with a chapter from Traoré on multi‐perspective modeling and holistic simulation for very complex systems analysis. The next chapter by Barros describes a unifying framework for hierarchical co‐simulation of CPS. This is followed by model‐based system of systems engineering tradeoff analytics by Markina‐Khusid et al. The next chapter by Mittal et al. considers a larger version of CPS, i.e. IoT, and the complexities associated with developing a risk assessment framework. Part III begins with a chapter from Castrol et al. on simulation model continuity for efficient development of embedded controllers in CPS. This is followed by another practical application by Henares et al. on CPS design methodology for prediction of symptomatic events in chronic diseases. In this chapter they present the entire lifecycle methodology for CPS engineering from concept to cloud deployment and execution. The next chapter by Bhadani et al. applies model‐based engineering to the subject of autonomy in CPS. Part IV begins with a chapter by Furness on providing various perspectives on securing CPS. This is supported by the next chapter by Haque et al. on CPS resilience and discusses frameworks, complexities, and future directions on resilient systems engineering. The next chapter by Suarez and Demareth discusses the creation of social structures employing CPS. The Part V incorporates another chapter by the editors on the way forward and provides a research agenda for addressing complexity in application of M&S for CPS engineering.

Editing this book was a rewarding journey that offered plenty of opportunities to learn and discover. We invite you to share the exciting journey of CPS engineering that offers a wealth of opportunities for advancement at various levels. CPS are going to shape our lives: observing the well‐being of the elderly, observing our health, observing and optimizing our production systems, and many more opportunities. Just as our children can hardly imagine finding information on certain topics of interest – mainly due to home work or college projects – before Internet and Google, the new generation may no longer imagine how often we had to practice parallel parking, or how parcels were delivered only once a day. We hope to contribute to the efficient development of future CPS solutions with this compendium, and hopefully generate some ideas for scholars and researchers as well.

Saurabh Mittal1, PhD
The MITRE Corporation,
Fairborn, OH, USA


Andreas Tolk2, PhD
The MITRE Corporation,
Hampton, VA, USA

Notes

  1. 1, 2 The author's affiliation with the MITRE Corporation is provided for identification purposes only, and is not intended to convey or imply MITRE's concurrence with, or support for, the positions, opinions, or viewpoints expressed by the author. Approved for Public Release, Distribution Unlimited. Case: PR_18-2996-3.

Foreword

Several important global trends are occurring with regards to the advancement of cyber physical systems. Worldwide, significant technology‐driven advances are being pursued that address increasing cyber physical system performance, safety, and security while achieving design, development, and operational efficiencies that reduce cost. These trends include:

  • Significant investment in higher levels of automation for physical systems, including autonomous systems.
  • Increasing research and early applications of Artificial Intelligence to physical systems (AI), including addressing “Dependable AI” for high assurance AI‐software design and development.
  • Development of advanced static and dynamic analysis tools by the Modeling and Simulation community. The resulting Model‐based Systems Engineering (MBSE) analysis tools and methods address considerations related to the growing complexity of highly integrated System‐of‐System architectures.
  • Development of cyberattack resilient system architectures that can restore acceptable system operation in response to a real‐time detection of a functionally disabling cyberattack.

These initiatives bring with them increased complexity of system designs, with a corresponding set of risks that need to be addressed when designing new or significantly upgraded systems. These risks include:

  • Cyberattacks that include supply chain and insider attacks that can directly impact the application layer of physical systems and, in the worst case, can potentially result in operator or user injuries or loss of life.
  • Safety‐related incidents due to undetected deficiencies in system design.
  • Operator errors due to uncertainties related to human–machine roles under anomalous circumstances.

But, perhaps the most concerning risk is the recognized shortage of engineers and scientists who can contribute to the development of these new technologies and tools, as well as the shortage of the workforce that can productively employ the analysis tools that are designed to enable high productivity in the development and evaluation of new cyber physical system designs. This book helps to address this risk by providing a well‐constructed, selective set of articles that together offer the reader an integrated view of the state‐of‐the‐art in addressing complex cyber physical system design and development. By integrating the diverse set of articles, the book serves to compliment the education curriculums at Universities, which tends to separate the subjects discussed above into the curriculums of different departments (e.g. Mechanical Engineering for physical systems, Computer Science for AI and cybersecurity, Systems Engineering for complex system design analysis, etc.). As a result, I believe that books of this kind can play a significant role in enabling engineers to build on their formal education and prior experience in a manner that supports the greatly needed enhanced design and evaluation skills that the trends in cyber physical systems are calling for.

Reading this book is something that I highly recommend for engineers and scientists who are interested in becoming important participants in the global trends related to advancing the automation levels of cyber physical systems!

Barry Martin Horowitz
Member of the National Academy of Engineering
Munster Professor Systems and Information Engineering
University of Virginia

Previously CEO of The MITRE Corporation

Previously Virginia Cybersecurity Commissioner

March 2019

About the Editors

SAURABH MITTAL is Chief Scientist for Simulation, Experimentation, and Gaming Department at The MITRE Corporation in Fairborn, OH, Vice President‐Memberships and member of Board of Directors for Society of Modeling and Simulation (SCS) International in San Diego, CA. He holds a PhD and MS in Electrical and Computer Engineering with dual minors in Systems and Industrial Engineering, and Management and Information Systems from the University of Arizona, Tucson. He has co‐authored over 100 publications as book chapters, journal articles, and conference proceedings including 3 books, covering topics in the areas of complex systems, system of systems, complex adaptive systems, emergent behavior, modeling and simulation (M&S), and M&S‐based systems engineering across many disciplines. He serves on many international conference program/technical committees, as a referee for prestigious scholastic journals and on the editorial boards of Transactions of SCS, Journal of Defense M&S and Enterprise Architecture Body of Knowledge. He is a recipient of Herculean Effort Leadership award from the University of Arizona, US DoD's highest civilian contractor recognition: Golden Eagle award, and Outstanding Service and Professional Contribution awards from SCS.

ANDREAS TOLK is a Senior Divisional Staff Member at The MITRE Corporation in Hampton, VA, and adjunct Full Professor at Old Dominion University in Norfolk, VA. He holds a PhD and MSc in Computer Science from the University of the Federal Armed Forces of Germany. His research interests include computational and epistemological foundations and constraints of modeling and simulation as well as mathematical foundations for the composition of model‐based solutions in computational sciences. He published more than 250 peer reviewed journal articles, book chapters, and conference papers, and edited 10 textbooks and compendia on Modeling and Simulation and Systems Engineering topics. He is a Fellow of the Society for Modeling and Simulation and Senior Member of IEEE and the Association for Computing Machinery.

List of Contributors

Jose L. Ayala
Complutense University of Madrid
Madrid
Spain

Fernando J. Barros
Department of Informatics Engineering
University of Coimbra
Coimbra
Portugal

Rahul Bhadani
Department of Electrical and Computer Engineering
University of Arizona
Tucson
AZ
USA

Marco Biagini
NATO Modelling & Simulation Center of Excellence (M&S COE)
Italy

Agostino Bruzzone
Genoa University
Genoa
Italy

Matt Bunting
Department of Electrical and Computer Engineering
University of Arizona
Tucson
AZ
USA

Sheila A. Cane
Quinnipiac University
Hamden
CT
USA

Sebastian Castro
MathWorks
Natick
MA
USA

Rodrigo Castro
Departamento de Computación, FCEyN
Universidad de Buenos Aires and Instituto de Ciencias de la Computación, CONICET
Buenos Aires
Argentina

Fabio Corona
NATO Modelling & Simulation Center of Excellence (M&S COE)
Italy

Judith Dahmann
The MITRE Corporation
McLean
VA
USA

Loren Demerath
Department of Sociology
Centenary College of Louisiana
Shreveport
LA
USA

Zach Furness
INOVA Health Systems
Sterling
VA
USA

Juan I. Giribet
Departamento de Ingeniería Electrónica y Matemática, FIUBA
Universidad de Buenos Aires, and Instituto Argentino de Matemática Alberto Calderón, CONICET
Buenos Aires
Argentina

Md Ariful Haque
Computational Modeling and Simulation Engineering
Old Dominion University
Norfolk
VA
USA

Richard B. Harris
The MITRE Corporation
McLean
VA
USA

Kevin Henares
Complutense University of Madrid
Madrid
Spain

Ryan Jacobs
The MITRE Corporation
McLean
VA
USA

Jason Jones
NATO Modelling & Simulation Center of Excellence (M&S COE)
Italy

Bheshaj Krishnappa
Risk Analysis and Mitigation
ReliabilityFirst Corporation
Cleveland
OH
USA

Ezequiel Pecker Marcosig
Departamento de Ingeniería Electrónica, FIUBA
Universidad de Buenos Aires and Instituto de Ciencias de la Computación, CONICET
Buenos Aires
Argentina

Aleksandra Markina‐Khusid
The MITRE Corporation
McLean
VA
USA

Jan Mazal
NATO Modelling & Simulation Center of Excellence (M&S COE)
Italy

Saurabh Mittal
The MITRE Corporation
Fairborn
OH
USA

Pieter J. Mosterman
MathWorks
Natick
MA
USA

Josué Pagán
Technical University of Madrid
Madrid
Spain

Akshay H. Rajhans
MathWorks
Natick
MA
USA

José L. Risco‐Martín
Complutense University of Madrid
Madrid
Spain

Charles Schmidt
The MITRE Corporation
McLean
VA
USA

Sachin Shetty
Computational Modeling and Simulation Engineering
Old Dominion University
Norfolk
VA
USA

Jonathan Sprinkle
Department of Electrical and Computer Engineering
The University of Arizona
Tucson
AZ
USA

E. Dante Suarez
School of Business, Department of Finance and Decision Sciences
Trinity University
San Antonio
TX
USA

Andreas Tolk
The MITRE Corporation
Hampton
VA
USA

Mamadou K. Traoré
IMS UMR CNRS
University of Bordeaux
Bordeaux
France

John Tufarolo
Research Innovations, Inc.
Alexandria
VA
USA

Michele Turi
NATO Modelling & Simulation Center of Excellence (M&S COE)
Italy

Marina Zapater
Swiss Federal Institute of Technology Lausanne
Lausanne
Switzerland