@article{eisele2020Safe,
  author = {Eisele, Scott and Eghtesad, Taha and Campanelli, Keegan and Agrawal, Prakhar and Laszka, Aron and Dubey, Abhishek},
  title = {Safe and Private Forward-Trading Platform for Transactive Microgrids},
  year = {2021},
  issue_date = {January 2021},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  volume = {5},
  number = {1},
  tag = {decentralization, power},
  issn = {2378-962X},
  url = {https://doi.org/10.1145/3403711},
  doi = {10.1145/3403711},
  journal = {ACM Trans. Cyber-Phys. Syst.},
  month = jan,
  articleno = {8},
  numpages = {29},
  keywords = {privacy, cyber-physical system, decentralized application, smart contract, transactive energy, Smart grid, distributed ledger, blockchain}
}

Transactive microgrids have emerged as a transformative solution for the problems faced by distribution system operators due to an increase in the use of distributed energy resources and rapid growth in renewable energy generation. Transactive microgrids are tightly coupled cyber and physical systems, which require resilient and robust financial markets where transactions can be submitted and cleared, while ensuring that erroneous or malicious transactions cannot destabilize the grid. In this paper, we introduce TRANSAX, a novel decentralized platform for transactive microgrids. TRANSAX enables participants to trade in an energy futures market, which improves efficiency by finding feasible matches for energy trades, reducing the load on the distribution system operator. TRANSAX provides privacy to participants by anonymizing their trading activity using a distributed mixing service, while also enforcing constraints that limit trading activity based on safety requirements, such as keeping power flow below line capacity. We show that TRANSAX can satisfy the seemingly conflicting requirements of efficiency, safety, and privacy, and we demonstrate its performance using simulation results.

@inproceedings{resonate2021,
  author = {Hartsell, Charles and Ramakrishna, Shreyas and Dubey, Abhishek and Stojcsics, Daniel and Mahadevan, Nag and Karsai, Gabor},
  title = {ReSonAte: A Runtime Risk Assessment Framework for Autonomous Systems},
  booktitle = {16th {International} Symposium on Software Engineering for Adaptive and Self-Managing Systems, {SEAMS} 2021},
  year = {2021},
  tag = {ai4cps},
  category = {selectiveconference},
  project = {cps-middleware,cps-reliability}
}

Autonomous Cyber-Physical Systems (CPSs) are often required to handle uncertainties and self-manage the system operation in response to problems and increasing risk in the operating paradigm. This risk may arise due to distribution shifts, environmental context, or failure of software or hardware components. Traditional techniques for risk assessment focus on design-time techniques such as hazard analysis, risk reduction, and assurance cases among others. However, these static, design time techniques do not consider the dynamic contexts and failures the systems face at runtime. We hypothesize that this requires a dynamic assurance approach that computes the likelihood of unsafe conditions or system failures considering the safety requirements, assumptions made at design time, past failures in a given operating context, and the likelihood of system component failures. We introduce the ReSonAte dynamic risk estimation framework for autonomous systems. ReSonAte reasons over Bow-Tie Diagrams (BTDs), which capture information about hazard propagation paths and control strategies. Our innovation is the extension of the BTD formalism with attributes for modeling the conditional relationships with the state of the system and environment. We also describe a technique for estimating these conditional relationships and equations for estimating risk-based on the state of the system and environment. To help with this process, we provide a scenario modeling procedure that can use the prior distributions of the scenes and threat conditions to generate the data required for estimating the conditional relationships. To improve scalability and reduce the amount of data required, this process considers each control strategy in isolation and composes several single-variate distributions into one complete multi-variate distribution for the control strategy in question. Lastly, we describe the effectiveness of our approach using two separate autonomous system simulations: CARLA and an unmanned underwater vehicle.

@article{ramakrishna2020dynamic,
  title = {Dynamic-weighted simplex strategy for learning enabled cyber physical systems},
  journal = {Journal of Systems Architecture},
  volume = {111},
  pages = {101760},
  year = {2020},
  tag = {a14cps},
  issn = {1383-7621},
  doi = {https://doi.org/10.1016/j.sysarc.2020.101760},
  url = {https://www.sciencedirect.com/science/article/pii/S1383762120300540},
  author = {Ramakrishna, Shreyas and Harstell, Charles and Burruss, Matthew P. and Karsai, Gabor and Dubey, Abhishek},
  keywords = {Convolutional Neural Networks, Learning Enabled Components, Reinforcement Learning, Simplex Architecture}
}

Cyber Physical Systems (CPS) have increasingly started using Learning Enabled Components (LECs) for performing perception-based control tasks. The simple design approach, and their capability to continuously learn has led to their widespread use in different autonomous applications. Despite their simplicity and impressive capabilities, these components are difficult to assure, which makes their use challenging. The problem of assuring CPS with untrusted controllers has been achieved using the Simplex Architecture. This architecture integrates the system to be assured with a safe controller and provides a decision logic to switch between the decisions of these controllers. However, the key challenges in using the Simplex Architecture are: (1) designing an effective decision logic, and (2) sudden transitions between controller decisions lead to inconsistent system performance. To address these research challenges, we make three key contributions: (1) dynamic-weighted simplex strategy – we introduce “weighted simplex strategy” as the weighted ensemble extension of the classical Simplex Architecture. We then provide a reinforcement learning based mechanism to find dynamic ensemble weights, (2) middleware framework – we design a framework that allows the use of the dynamic-weighted simplex strategy, and provides a resource manager to monitor the computational resources, and (3) hardware testbed – we design a remote-controlled car testbed called DeepNNCar to test and demonstrate the aforementioned key concepts. Using the hardware, we show that the dynamic-weighted simplex strategy has 60% fewer out-of-track occurrences (soft constraint violations), while demonstrating higher optimized speed (performance) of 0.4 m/s during indoor driving than the original LEC driven system.

@inproceedings{eisele2020mechanisms,
  title = {Mechanisms for Outsourcing Computation via a Decentralized Market},
  author = {Eisele, Scott and Eghtesad, Taha and Troutman, Nicholas and Laszka, Aron and Dubey, Abhishek},
  year = {2020},
  tag = {platform,decentralization},
  booktitle = {14TH ACM International Conference on Distributed and Event Based Systems},
  keywords = {transactive},
  category = {selectiveconference}
}

As the number of personal computing and IoT devices grows rapidly, so does the amount of computational power that is available at the edge. Since many of these devices are often idle, there is a vast amount of computational power that is currently untapped, and which could be used for outsourcing computation. Existing solutions for harnessing this power, such as volunteer computing (e.g., BOINC), are centralized platforms in which a single organization or company can control participation and pricing. By contrast, an open market of computational resources, where resource owners and resource users trade directly with each other, could lead to greater participation and more competitive pricing. To provide an open market, we introduce MODiCuM, a decentralized system for outsourcing computation. MODiCuM deters participants from misbehaving-which is a key problem in decentralized systems-by resolving disputes via dedicated mediators and by imposing enforceable fines. However, unlike other decentralized outsourcing solutions, MODiCuM minimizes computational overhead since it does not require global trust in mediation results. We provide analytical results proving that MODiCuM can deter misbehavior, and we evaluate the overhead of MODiCuM using experimental results based on an implementation of our platform.

@article{Hasan2020,
  author = {Hasan, Saqib and Dubey, Abhishek and Karsai, Gabor and Koutsoukos, Xenofon},
  title = {A game-theoretic approach for power systems defense against dynamic cyber-attacks},
  journal = {International Journal of Electrical Power \& Energy Systems},
  year = {2020},
  volume = {115},
  issn = {0142-0615},
  doi = {https://doi.org/10.1016/j.ijepes.2019.105432},
  file = {:Hasan2020-A_Game_Theoretic_Approach_for_Power_Systems_Defense_against_Dynamic_Cyber_Attacks.pdf:PDF},
  keywords = {Cascading failures, Cyber-attack, Dynamic attack, Game theory, Resilience, Smart grid, Static attack, smartgrid, reliability},
  project = {cps-reliability},
  tag = {platform,power},
  url = {http://www.sciencedirect.com/science/article/pii/S0142061519302807}
}

Technological advancements in today’s electrical grids give rise to new vulnerabilities and increase the potential attack surface for cyber-attacks that can severely affect the resilience of the grid. Cyber-attacks are increasing both in number as well as sophistication and these attacks can be strategically organized in chronological order (dynamic attacks), where they can be instantiated at different time instants. The chronological order of attacks enables us to uncover those attack combinations that can cause severe system damage but this concept remained unexplored due to the lack of dynamic attack models. Motivated by the idea, we consider a game-theoretic approach to design a new attacker-defender model for power systems. Here, the attacker can strategically identify the chronological order in which the critical substations and their protection assemblies can be attacked in order to maximize the overall system damage. However, the defender can intelligently identify the critical substations to protect such that the system damage can be minimized. We apply the developed algorithms to the IEEE-39 and 57 bus systems with finite attacker/defender budgets. Our results show the effectiveness of these models in improving the system resilience under dynamic attacks.

@inproceedings{Pettet2020,
  author = {Pettet, Geoffrey and Mukhopadhyay, Ayan and Kochenderfer, Mykel and Vorobeychik, Yevgeniy and Dubey, Abhishek},
  title = {On Algorithmic Decision Procedures in Emergency Response Systems in Smart and Connected Communities},
  booktitle = {Proceedings of the 19th Conference on Autonomous Agents and MultiAgent Systems, {AAMAS} 2020, Auckland, New Zealand},
  year = {2020},
  tag = {ai4cps, decentralization,incident},
  category = {selectiveconference},
  keywords = {emergency, performance},
  project = {smart-emergency-response,smart-cities},
  timestamp = {Wed, 17 Jan 2020 07:24:00 +0200}
}

Emergency Response Management (ERM) is a critical problem faced by communities across the globe. Despite its importance, it is common for ERM systems to follow myopic and straight-forward decision policies in the real world. Principled approaches to aid decision-making under uncertainty have been explored in this context but have failed to be accepted into real systems. We identify a key issue impeding their adoption — algorithmic approaches to emergency response focus on reactive, post-incident dispatching actions, i.e. optimally dispatching a responder after incidents occur. However, the critical nature of emergency response dictates that when an incident occurs, first responders always dispatch the closest available responder to the incident. We argue that the crucial period of planning for ERM systems is not post-incident, but between incidents. However, this is not a trivial planning problem - a major challenge with dynamically balancing the spatial distribution of responders is the complexity of the problem. An orthogonal problem in ERM systems is to plan under limited communication, which is particularly important in disaster scenarios that affect communication networks. We address both the problems by proposing two partially decentralized multi-agent planning algorithms that utilize heuristics and the structure of the dispatch problem. We evaluate our proposed approach using real-world data, and find that in several contexts, dynamic re-balancing the spatial distribution of emergency responders reduces both the average response time as well as its variance.

@article{Sun2019,
  author = {Sun, Fangzhou and Dubey, Abhishek and White, Jules and Gokhale, Aniruddha},
  title = {Transit-hub: a smart public transportation decision support system with multi-timescale analytical services},
  journal = {Cluster Computing},
  year = {2019},
  volume = {22},
  tag = {transit},
  number = {Suppl 1},
  pages = {2239--2254},
  month = jan,
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/cluster/SunDWG19},
  doi = {10.1007/s10586-018-1708-z},
  file = {:Sun2019-Transit-hub_a_smart_public_transportation_decision_support_system_with_multi-timescale_analytical_services.pdf:PDF},
  keywords = {transit},
  project = {smart-cities,smart-transit},
  timestamp = {Wed, 21 Aug 2019 01:00:00 +0200},
  url = {https://doi.org/10.1007/s10586-018-1708-z}
}

Public transit is a critical component of a smart and connected community. As such, citizens expect and require accurate information about real-time arrival/departures of transportation assets. As transit agencies enable large-scale integration of real-time sensors and support back-end data-driven decision support systems, the dynamic data-driven applications systems (DDDAS) paradigm becomes a promising approach to make the system smarter by providing online model learning and multi-time scale analytics as part of the decision support system that is used in the DDDAS feedback loop. In this paper, we describe a system in use in Nashville and illustrate the analytic methods developed by our team. These methods use both historical as well as real-time streaming data for online bus arrival prediction. The historical data is used to build classifiers that enable us to create expected performance models as well as identify anomalies. These classifiers can be used to provide schedule adjustment feedback to the metro transit authority. We also show how these analytics services can be packaged into modular, distributed and resilient micro-services that can be deployed on both cloud back ends as well as edge computing resources.

@inproceedings{Hartsell2019b,
  author = {Hartsell, Charles and Mahadevan, Nagabhushan and Ramakrishna, Shreyas and Dubey, Abhishek and Bapty, Theodore and Johnson, Taylor T. and Koutsoukos, Xenofon D. and Sztipanovits, Janos and Karsai, Gabor},
  title = {{CPS} Design with Learning-Enabled Components: {A} Case Study},
  booktitle = {Proceedings of the 30th International Workshop on Rapid System Prototyping, {RSP} 2019, New York, NY, USA, October 17-18, 2019},
  year = {2019},
  pages = {57--63},
  tag = {ai4cps},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/rsp/HartsellMRDBJKS19},
  category = {selectiveconference},
  doi = {10.1145/3339985.3358491},
  file = {:Hartsell2019b-CPS_Design_with_Learning-Enabled_Components_A_Case_Study.pdf:PDF},
  keywords = {assurance},
  project = {cps-autonomy},
  timestamp = {Thu, 28 Nov 2019 12:43:50 +0100},
  url = {https://doi.org/10.1145/3339985.3358491}
}

Cyber-Physical Systems (CPS) are used in many applications where they must perform complex tasks with a high degree of autonomy in uncertain environments. Traditional design flows based on domain knowledge and analytical models are often impractical for tasks such as perception, planning in uncertain environments, control with ill-defined objectives, etc. Machine learning based techniques have demonstrated good performance for such difficult tasks, leading to the introduction of Learning-Enabled Components (LEC) in CPS. Model based design techniques have been successful in the development of traditional CPS, and toolchains which apply these techniques to CPS with LECs are being actively developed. As LECs are critically dependent on training and data, one of the key challenges is to build design automation for them. In this paper, we examine the development of an autonomous Unmanned Underwater Vehicle (UUV) using the Assurance-based Learning-enabled Cyber-physical systems (ALC) Toolchain. Each stage of the development cycle is described including architectural modeling, data collection, LEC training, LEC evaluation and verification, and system-level assurance.

@article{Pradhan2018,
  author = {Pradhan, Subhav and Dubey, Abhishek and Khare, Shweta and Nannapaneni, Saideep and Gokhale, Aniruddha S. and Mahadevan, Sankaran and Schmidt, Douglas C. and Lehofer, Martin},
  title = {{CHARIOT:} Goal-Driven Orchestration Middleware for Resilient IoT Systems},
  journal = {{TCPS}},
  year = {2018},
  volume = {2},
  number = {3},
  pages = {16:1--16:37},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/tcps/PradhanDKNGMSL18},
  doi = {10.1145/3134844},
  tag = {ai4cps,platform},
  file = {:Pradhan2018-CHARIOT_Goal-Driven_Orchestration_Middleware_for_Resilient_IoT_Systems.pdf:PDF},
  keywords = {reliability, middleware},
  project = {cps-middleware,cps-reliability},
  timestamp = {Wed, 21 Nov 2018 00:00:00 +0100},
  url = {https://doi.org/10.1145/3134844}
}

An emerging trend in Internet of Things (IoT) applications is to move the computation (cyber) closer to the source of the data (physical). This paradigm is often referred to as edge computing. If edge resources are pooled together they can be used as decentralized shared resources for IoT applications, providing increased capacity to scale up computations and minimize end-to-end latency. Managing applications on these edge resources is hard, however, due to their remote, distributed, and (possibly) dynamic nature, which necessitates autonomous management mechanisms that facilitate application deployment, failure avoidance, failure management, and incremental updates. To address these needs, we present CHARIOT, which is orchestration middleware capable of autonomously managing IoT systems consisting of edge resources and applications. CHARIOT implements a three-layer architecture. The topmost layer comprises a system description language, the middle layer comprises a persistent data storage layer and the corresponding schema to store system information, and the bottom layer comprises a management engine that uses information stored persistently to formulate constraints that encode system properties and requirements, thereby enabling the use of Satisfiability Modulo Theories (SMT) solvers to compute optimal system (re)configurations dynamically at runtime. This paper describes the structure and functionality of CHARIOT and evaluates its efficacy as the basis for a smart parking system case study that uses sensors to manage parking spaces.

@article{GarciaValls2018,
  author = {Garc{\'{\i}}a{-}Valls, Marisol and Dubey, Abhishek and Botti, Vicent J.},
  title = {Introducing the new paradigm of Social Dispersed Computing: Applications, Technologies and Challenges},
  journal = {Journal of Systems Architecture - Embedded Systems Design},
  year = {2018},
  volume = {91},
  tag = {platform,decentralization},
  pages = {83--102},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/jsa/Garcia-VallsDB18},
  doi = {10.1016/j.sysarc.2018.05.007},
  file = {:Garcia-Valls2018-Introducing_the_new_paradigm_of_Social_Dispersed_Computing_Applications_Technologies_and_Challenges.pdf:PDF},
  keywords = {middleware},
  project = {cps-middleware},
  timestamp = {Mon, 16 Sep 2019 01:00:00 +0200},
  url = {https://doi.org/10.1016/j.sysarc.2018.05.007}
}

If last decade viewed computational services as a utilitythen surely this decade has transformed computation into a commodity. Computation is now progressively integrated into the physical networks in a seamless way that enables cyber-physical systems (CPS) and the Internet of Things (IoT) meet their latency requirements. Similar to the concept of “platform as a service” or “software as a service”, both cloudlets and fog computing have found their own use cases. Edge devices (that we call end or user devices for disambiguation) play the role of personal computers, dedicated to a user and to a set of correlated applications. In this new scenario, the boundaries between the network node, the sensor, and the actuator are blurring, driven primarily by the computation power of IoT nodes like single board computers and the smartphones. The bigger data generated in this type of networks needs clever, scalable, and possibly decentralized computing solutions that can scale independently as required. Any node can be seen as part of a graph, with the capacity to serve as a computing or network router node, or both. Complex applications can possibly be distributed over this graph or network of nodes to improve the overall performance like the amount of data processed over time. In this paper, we identify this new computing paradigm that we call Social Dispersed Computing, analyzing key themes in it that includes a new outlook on its relation to agent based applications. We architect this new paradigm by providing supportive application examples that include next generation electrical energy distribution networks, next generation mobility services for transportation, and applications for distributed analysis and identification of non-recurring traffic congestion in cities. The paper analyzes the existing computing paradigms (e.g., cloud, fog, edge, mobile edge, social, etc.), solving the ambiguity of their definitions; and analyzes and discusses the relevant foundational software technologies, the remaining challenges, and research opportunities.

@article{Balasubramanian2015,
  author = {Balasubramanian, Daniel and Dubey, Abhishek and Otte, William and Levendovszky, Tihamer and Gokhale, Aniruddha S. and Kumar, Pranav Srinivas and Emfinger, William and Karsai, Gabor},
  title = {{DREMS} {ML:} {A} wide spectrum architecture design language for distributed computing platforms},
  journal = {Sci. Comput. Program.},
  year = {2015},
  tag = {platform},
  volume = {106},
  pages = {3--29},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/scp/Balasubramanian15},
  doi = {10.1016/j.scico.2015.04.002},
  file = {:Balasubramanian2015-DREMS_ML_A_wide_spectrum_architecture_design_language_for_distributed_computing_platforms.pdf:PDF},
  keywords = {middleware},
  project = {cps-middleware},
  timestamp = {Sat, 27 May 2017 01:00:00 +0200},
  url = {https://doi.org/10.1016/j.scico.2015.04.002}
}

Complex sensing, processing and control applications running on distributed platforms are difficult to design, develop, analyze, integrate, deploy and operate, especially if resource constraints, fault tolerance and security issues are to be addressed. While technology exists today for engineering distributed, real-time component-based applications, many problems remain unsolved by existing tools. Model-driven development techniques are powerful, but there are very few existing and complete tool chains that offer an end-to-end solution to developers, from design to deployment. There is a need for an integrated model-driven development environment that addresses all phases of application lifecycle including design, development, verification, analysis, integration, deployment, operation and maintenance, with supporting automation in every phase. Arguably, a centerpiece of such a model-driven environment is the modeling language. To that end, this paper presents a wide-spectrum architecture design language called DREMS ML that itself is an integrated collection of individual domain-specific sub-languages. We claim that the language promotes “correct-by-construction” software development and integration by supporting each individual phase of the application lifecycle. Using a case study, we demonstrate how the design of DREMS ML impacts the development of embedded systems.

@article{Levendovszky2014,
  author = {Levendovszky, Tihamer and Dubey, Abhishek and Otte, William and Balasubramanian, Daniel and Coglio, Alessandro and Nyako, Sandor and Emfinger, William and Kumar, Pranav Srinivas and Gokhale, Aniruddha S. and Karsai, Gabor},
  title = {Distributed Real-Time Managed Systems: {A} Model-Driven Distributed Secure Information Architecture Platform for Managed Embedded Systems},
  journal = {{IEEE} Software},
  year = {2014},
  volume = {31},
  number = {2},
  tag = {platform},
  pages = {62--69},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/journals/software/LevendovszkyDOBCNEKGK14},
  doi = {10.1109/MS.2013.143},
  file = {:Levendovszky2014-Distributed_Real_Time_Managed_Systems.pdf:PDF},
  keywords = {middleware},
  project = {cps-middleware,cps-reliability},
  timestamp = {Thu, 18 May 2017 01:00:00 +0200},
  url = {https://doi.org/10.1109/MS.2013.143}
}

Architecting software for a cloud computing platform built from mobile embedded devices incurs many challenges that aren’t present in traditional cloud computing. Both effectively managing constrained resources and isolating applications without adverse performance effects are needed. A practical design- and runtime solution incorporates modern software development practices and technologies along with novel approaches to address these challenges. The patterns and principles manifested in this system can potentially serve as guidelines for current and future practitioners in this field.

@inproceedings{Roy2011a,
  author = {Roy, Nilabja and Dubey, Abhishek and Gokhale, Aniruddha S.},
  title = {Efficient Autoscaling in the Cloud Using Predictive Models for Workload Forecasting},
  booktitle = {{IEEE} International Conference on Cloud Computing, {CLOUD} 2011, Washington, DC, USA, 4-9 July, 2011},
  year = {2011},
  pages = {500--507},
  tag = {platform},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/IEEEcloud/RoyDG11},
  category = {selectiveconference},
  doi = {10.1109/CLOUD.2011.42},
  file = {:Roy2011a-Efficient_Autoscaling_in_the_Cloud_Using_Predictive_Models_for_Workload_Forecasting.pdf:PDF},
  keywords = {performance},
  project = {cps-middleware},
  timestamp = {Wed, 16 Oct 2019 14:14:54 +0200},
  url = {https://doi.org/10.1109/CLOUD.2011.42}
}

Large-scale component-based enterprise applications that leverage Cloud resources expect Quality of Service(QoS) guarantees in accordance with service level agreements between the customer and service providers. In the context of Cloud computing, auto scaling mechanisms hold the promise of assuring QoS properties to the applications while simultaneously making efficient use of resources and keeping operational costs low for the service providers. Despite the perceived advantages of auto scaling, realizing the full potential of auto scaling is hard due to multiple challenges stemming from the need to precisely estimate resource usage in the face of significant variability in client workload patterns. This paper makes three contributions to overcome the general lack of effective techniques for workload forecasting and optimal resource allocation. First, it discusses the challenges involved in auto scaling in the cloud. Second, it develops a model-predictive algorithm for workload forecasting that is used for resource auto scaling. Finally, empirical results are provided that demonstrate that resources can be allocated and deal located by our algorithm in a way that satisfies both the application QoS while keeping operational costs low.

@inproceedings{Mahadevan2011,
  author = {Mahadevan, Nagabhushan and Dubey, Abhishek and Karsai, Gabor},
  title = {Application of software health management techniques},
  booktitle = {2011 {ICSE} Symposium on Software Engineering for Adaptive and Self-Managing Systems, {SEAMS} 2011, Waikiki, Honolulu , HI, USA, May 23-24, 2011},
  year = {2011},
  pages = {1--10},
  tag = {platform},
  bibsource = {dblp computer science bibliography, https://dblp.org},
  biburl = {https://dblp.org/rec/bib/conf/icse/MahadevanDK11},
  category = {selectiveconference},
  doi = {10.1145/1988008.1988010},
  file = {:Mahadevan2011-Application_of_software_health_management_techniques.pdf:PDF},
  keywords = {performance, reliability},
  project = {cps-middleware,cps-reliability},
  timestamp = {Tue, 06 Nov 2018 00:00:00 +0100},
  url = {https://doi.org/10.1145/1988008.1988010}
}

The growing complexity of software used in large-scale, safety critical cyber-physical systems makes it increasingly difficult to expose and hence correct all potential defects. There is a need to augment the existing fault tolerance methodologies with new approaches that address latent software defects exposed at runtime. This paper describes an approach that borrows and adapts traditional ‘System Health Management’ techniques to improve software dependability through simple formal specification of runtime monitoring, diagnosis, and mitigation strategies. The two-level approach to health management at the component and system level is demonstrated on a simulated case study of an Air Data Inertial Reference Unit (ADIRU). An ADIRU was categorized as the primary failure source for the in-flight upset caused in the Malaysian Air flight 124 over Perth, Australia in 2005.