As a side result of the largest literature survey on digital twins to date,

• M. Dalibor, N. Jansen, B. Rumpe, D. Schmalzing, L. Wachtmeister, M. Wimmer, A. Wortmann: A Cross-Domain Systematic Mapping Study on Software Engineering for Digital Twins. In: Journal of Systems and Software, 111361,

we have produced a collection of 112 definitions of the term “digital twin” from the publications of our corpus. This collection is reproduced below.

If you want to add a definition or modify an entry, please create a pull request.

Definitions

• “An always in sync digital model of existing manufacturing cells”. B. A. Talkhestani, N. Jazdi, W. Schlögl , M. Weyrich. A concept in synchronization of virtual production system with real factory based on anchor-point method. In: Procedia CIRP, 2018

• “An always current digital image of the production system”. F. Biesinger, D. Meike, B. Krass, M. Weyrich. A digital twin for production planning based on cyber-physical systems: A Case Study for a Cyber-Physical System-Based Creation of a Digital Twin. In: 12TH CIRP CONFERENCE ON INTELLIGENT COMPUTATION IN MANUFACTURING ENGINEERING, 2019

• “A digital twin is a virtual replica of the printing hardware”. T. Mukherjee, T. Debroy. A digital twin for rapid qualification of 3D printed metallic components. In: APPLIED MATERIALS TODAY, 2019

• “a virtual mapping of a physical product”. A. Detzner, M. Eigner. A digital twin for root cause analysis and product quality monitoring. In: Proceedings of International Design Conference, DESIGN, 2018

• “In the context of Industry 4.0, the Digital Twin is introduced as a framework for mirroring certain aspects of the underlying physical entities in the manufacturing processes”. K. Josifovska, E. Yigitbas, G. Engels. A Digital Twin-Based Multi-modal UI Adaptation Framework for Assistance Systems in Industry 4.0. In: Human-Computer Interaction. Design Practice in Contemporary Societies, 2019

• “Digital representation of any real-world counterpart allowing its management”. M. Dietz, B. Putz, G. Pernul. A Distributed Ledger Approach to Digital Twin Secure Data Sharing. In: Data and Applications Security and Privacy XXXIII, 2019

• “a Digital Twin is a digital avatar encompassing CPS data and intelligence; it represents structure, semantics and behavior of the associated CPS, providing services to mesh the virtual and physical worlds “. M. Ciavotta, M. Alge, S. Menato, D. Rovere, P. Pedrazzoli. A Microservice-based Middleware for the Digital Factory. In: Procedia Manufacturing, 2017

• “digital equivalent to a physical product”. G. Avventuroso, M. Silvestri, P. Pedrazzoli. A Networked Production System to Implement Virtual Enterprise and Product Lifecycle Information Loops. In: IFAC-PapersOnLine, 2017

• “While in the context of smart manufacturing, the term “digital twin” is more broadly applied to modeling, simulation and visualization aspects based on various artifacts and data collected during operation, we use it to describe emulated or simulated devices that may be connected to an emulated network.”. M. Eckhart, A. Ekelhart. A Specification-based State Replication Approach for Digital Twins. In: Proceedings of the 2018 Workshop on Cyber-Physical Systems Security and PrivaCy, 2018

• “A digital twin is defined as the predictive and validated model of the manufacturing process with the intention to support approval documentation.”. S. Zobel-Roos, A. Schmidt, F. Mestmäcker, M. Mouellef, M. Huter, L. Uhlenbrock, M. Kornecki, L. Lohmann, R. Ditz, J. Strube. [Accelerating biologics manufacturing by modeling or: Is Approval under the QbD and PAT approaches demanded by authorities acceptable without a digital-twin?](https://www.mdpi.com/2227-9717/7/2/94. In: Processes, 2019

• “the DT is a set of virtual information that fully describes a potential or actual physical production from the micro atomic level to the macro geometrical level”. Y. Zheng, S. Yang, H. Cheng. An application framework of digital twin and its case study. In: Journal of Ambient Intelligence and Humanized Computing, 2019

• “a Digital Twin of a real distributed product is a virtual reflection, which can describe the exhaustive physical and functional properties of the product along the whole life cycle and can deliver and receive product information”. R. Tharma, R. Winter, M. Eigner. An approach for the implementation of the digital twin in the automotive wiring harness field. In: Proceedings of International Design Conference, DESIGN, 2018

• “the creation on the basis of Unisim Design software-hardware solution “cloud” models of technological units and combining them into a single integrated “cloud” model of the production complex, called “digital twin” which in fact represents a virtual projection of the industrial facility into the “cloud”‘_ N.R. Yusupbekov, F.R. Abdurasulov, F.T. Adilov, A.I. Ivanyan. Application of cloud technologies for optimization of complex processes of industrial enterprises. In: Advances in Intelligent Systems and Computing, 2019

• “The digital twin concept is a functional system of continous optimization, which includes physical production together with its digital ‘copy’.”. E. Sujová, H. Čierna, I. Zabińska. Application of digitization procedures of production in practice. In: Management Systems in Production Engineering, 2019”

• “Digital twins of technological equipment are infrastructure components of production companies of the Industry 4.0 functioning in the level of cloud services.”. D.A. Zakoldaev, A.V. Gurjanov, D.R. Kochubey, I.O. Zharinov. Application of imitation modelling means to create digital twins of the Industry 4.0 company technological equipment. In: IOP Conference Series: Materials Science and Engineering, 2018

• “the DT is a simulation method that can be used for evaluation and optimization”. Y. Tan, W. Yang, K. Yoshida, S. Takakuwa. Application of IoT-aided Simulation for a Cyber-physical System. In: Proceedings of the 2018 Winter Simulation Conference, 2018”

• “A DT consists of a virtual representation of a production system that is able to use sensory data, connected smart devices, mathematical models, and real-time data elaborations. The DT can be run on different simulation disciplines that are characterized by the synchronization of virtual and real systems”. Y. Tan, W. Yang, K. Yoshida, S. Takakuwa. Application of IoT-aided simulation to manufacturing systems in cyber-physical system. In: Machines, 2019

• “The idea behind this [Digital Twin] concept is to have a digital entity that behaves exactly (or as close as possible) as the real entity.”. D. Mejia, A. Moreno, O. Ruiz-SalgueroI, Ã. Barandiaran. Appraisal of open software for finite element simulation of 2D metal sheet laser cut. In: International Journal on Interactive Design and Manufacturing (IJIDeM), 2017

• “the digital twin is made up of measured data, managed information and models for the physical evolution of equipment. It simulates the real evolution of equipment, anticipating possible failures.”. M.F. Milazzo, G. Ancione, G. Scionti, P.A. Bragatto. Assessment and management of ageing of critical equipment at seveso sites. In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018, 2018

• “In assembly, the physical object has a digital twin, a CAD model that accurately resembles real features”. A. Blaga, L. Tamas. Augmented Reality for Digital Manufacturing. In: 2018 26th Mediterranean Conference on Control and Automation (MED), 2018

• “A Digital Twin (DT) is a digital replica of the physical assets of an industrial plant which contains the structure and the dynamics of how the devices and the process operate.”. G.S. Martínez, S. Sierla, T. Karhela, V. Vyatkin. Automatic generation of a simulation-based digital twin of an industrial process plant. In: Proceedings: IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, 2018

• “A digital twin is a dynamic digital model of an industrial object or physical device simulating the internal processes, engineering characteristics, and behavior of the actual object.”. A. K. Tugengold, V. P. Dimitrov, L. V. Borisova, M. V. Grankov, R. N. Voloshin. Autonomous Maintenance of Digital Equipment. In: Russian Engineering Research, 2019

• “In principle, digital twins are model-based representations of entities of the real world such as machines, cars, or persons.”. D. Schneider, M. Trapp. B-space: dynamic management and assurance of open systems of systems. In: Journal of Internet Services and Applications, 2018

• “Digital twin is a virtual representation, in the cyberspace, of a physical asset, process or system, possessing real-time information about the represented entity and a model of its behavior. “. A. Artem,L. Nazarenko, M. Camarinha-Matos. Basis for an Approach to Design Collaborative Cyber-Physical Systems. In: Technological Innovation for Industry and Service Systems, 2019

• “Digital twin is an exact cyber copy of a physical system that truely represents all of its functionalities.”. K. M. Alam, A. El Saddik. C2PS: A Digital Twin Architecture Reference Model for the Cloud-Based Cyber-Physical Systems. In: IEEE Access, 2017

• “A digital twin is a digital model of a real object containing lifecycle records and dynamic status data, which are synchronized in real-time. The model will be used to gain knowledge that can be transferred to the real object.”. M. Eisentrager, S. Adler, M. Kennel, S. Moser. Changeability in Engineering. In: 2018 IEEE International Conference on Engineering, Technology and Innovation, ICE/ITMC 2018 - Proceedings, 2018

• “the so-called ‘Digital Twin’ approach, which is a simplified numerical model.”. T. Barszcz, M. Zabaryłło. Concept of automated malfunction detection of large turbomachinery using machine learning on transient data. In: Diagnostyka, 2019

• “Digital twin, first of all, is a virtual replica of physical object’s (product’s), processes’, or systems’ operation condition.”. E. Kolbachev, V. Zharov, V. Tsukerman. Cost management for PLM systems: A way to improve the competitiveness in digital economy. In: IOP Conference Series: Materials Science and Engineering, 2019

• “A product virtual space is a digital twin that is attached to it to enable manufacturers and their clients to better manufacture, monitor, maintain and operate it throughout its life time cycles, i.e. from the product manufacturing date, through operation and to end of lifespan. “. A.R. Al-Ali, R. Gupta, A.A. Nabulsi. Cyber physical systems role in manufacturing technologies. In: AIP Conference Proceedings, 2018

• “A digital twin is a specialized type of CPS where the physical system’s components and attributes are mirroered into the cyber world. A digital twin enables real-time monitoring and decision making for various types of applications including medial and wellbeing applications”. F. Arafsha, F. Laamarti, A. El Saddik. Cyber-Physical System Framework for Measurement and Analysis of Physical Activities. In: ELECTRONICS, 2019

• “The basic definition of a Self-aware Digital Twin is that it represents as a set of clusters defined in the selected clustering process.”. N. Stojanovic, D. Milenovic. Data-driven Digital Twin approach for process optimization: An industry use case. In: Proceedings - 2018 IEEE International Conference on Big Data, Big Data 2018, 2019

• “A digital twin provides a digital replica of its physical counterpart which is virtually indistinguishable from its physical twin in the sense that it dynamically replicates the behavior and properties of the physical twin as well as enriches the replica with additional information about the physical counterpart. The conceptual model of a digital twin contains three main parts: (i) physical twin in the real world; (ii) digital twin in the virtual world; and (iii) the connections of input data and output command that ties the digital and real counterparts together.”. F. Oquendo. Dealing with Uncertainty in Software Architecture on the Internet-of-Things with Digital Twins, 2019

• “virtual digital model of the real network that consists of data from the real network”. R. Dong, C. She, W. Hardjawana, Y. Li, B. Vucetic. Deep Learning for Hybrid 5G Services in Mobile Edge Computing Systems: Learn from a Digital Twin. In: IEEE Transactions on Wireless Communications, 2019

• “A digital twin is a concept from the product life-cycle management (PLM) domain introduced by Grieves et al. (2017). It is a virtual representation of a specific physical product. The idea behind this concept is that the digital twin should be linked to the physical product throughout the product’s life-cycle and constantly mirror it.”. R. Bitton, T. Gluck, O. Stan, M. Inokuchi, Y. Ohta, Y. Yamada, T. Yagyu, Y. Elovici, A. Shabtai. Deriving a Cost-Effective Digital Twin of an ICS to Facilitate Security Evaluation. In: Computer Security, 2018

• “A digital twin can be defined as an integrated virtual model of a real-world system containing all of its physical information and functional units.”. K. T. Park,Y. W. Nam, H. S. Lee, S. J. Im, S. D. Noh, J. Y. Son, H. Kim. Design and implementation of a digital twin application for a connected micro smart factory. In: INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING, 2019

• “More simply, a DTM is a digital replica or virtual counterpart of a real entity, which can be assets, processes, systems, or even services. After being paired with a physical object, the DTM can perform the functions of the monitoring system and data analysing, aiming to catch and remove the problems even before they can occur.”. C. S. Shim, N. S. Dang, S. Lon, C. H. Jeon. Development of a bridge maintenance system for prestressed concrete bridges using 3D digital twin model. In: Structure and Infrastructure Engineering, 2019

• “An integrated model that represents, connects, and synchronizes a part of or the whole physical manufacturing system or process, enabled by historical and real-time data from the physical system or process”. G.Shao, D. Kibira. Digital manufacturing: Requirements and challenges for implementing digital surrogates. In: Proceedings - Winter Simulation Conference, 2019

• “[…] the digital twin is an object-oriented digital model of a physical asset that comprises all the data about the asset, including system, structural, engineering and technological models”. D. Kostenko, N. Kudryashov, M. Maystrishin, V. Onufriev, V. Potekhin, A. Vasiliev. Digital twin applications: Diagnostics, optimisation and prediction. In: Annals of DAAAM and Proceedings of the International DAAAM Symposium, 2018

• “Industrial Digital Twin (DT) - a digital copy of the real manufacturing sytem, which can be controlled and programmed in realtime directly from the computer application model of the industrial robot.”. V. Kuts, T. Otto, T. Tähemaa, Y. Bondarenko. Digital twin based synchronised control and simulation of the industrial robotic cell using virtual reality. In: Journal of Machine Engineering, 2019

• “A digital twin refers to a virtual representation of the real physical system that mirrors its state and behavior”. N. Karanjkar, A. Joglekar, S. Mohanty, V. Prabhu, D. Raghunath, R. Sundaresan. Digital twin for energy optimization in an SMT-PCB assembly line. In: Proceedings - 2018 IEEE International Conference on Internet of Things and Intelligence System, IOTAIS 2018, 2019

• “[…] an accurate simulation model, a digital twin, which can be used throughout the real system’s life span is created.”. A. Khan, M. Dahl, P. Falkman, M. Fabian. Digital Twin for Legacy Systems: Simulation Model Testing and Validation. In: IEEE International Conference on Automation Science and Engineering, 2018

• “Digital twin or BIM (Building information modeling) […] BIM is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life cycle; defined as existing from earliest conception to demolition.”. S. Kaewunruen, N. Xu. Digital twin for sustainability evaluation of railway station buildings. In: Frontiers in Built Environment, 2018

• “Digital Twin (DT) is defined as a very realistic model of the current state of the process and their own behavior in interaction with their environment in the real world [5]. […] However, the definition of a DT and its requirements are not yet fully established and lack of conceptual basis [3]. The characteristics a DT model should possess to be widely used in industry remains an open question in the literature.”. L. Fernando, C. S. Durão, S. Haag, R. Anderl, K. Schuetzer, E. Zancul. Digital Twin Requirements in the Context of Industry 4.0. In: Product Lifecycle Management to Support Industry 4.0, 2018

• “digital twin, a reference model to realize the convergence between physical and virtual space”. F. Tao, M. Zhang. Digital Twin Shop-Floor: A New Shop-Floor Paradigm Towards Smart Manufacturing. In: IEEE Access, 2017

• “Digital twin, a novel concept that refers to virtual substitutes of real world objects[…]. The idea of digital twin is to create a digital counterpart to mimic the characteristics and behaviors of its corresponding twin.”. K. Yan, W. Xu, B. Yao, Z. Zhou, D.T. Pham. Digital Twin-Based Energy Modeling of Industrial Robots. In: Communications in Computer and Information Science, 2018

• “Digital twin technology refers to the mehtod of describing and modeling a physical entity’s characteristics, behavior, and performance by means of digital technology.”. S. Meng, S. Tang, Y. Zhu, C. Chen. Digital Twin-Driven Control Method for Robotic Automatic Assembly System. In: 2ND INTERNATIONAL CONFERENCE ON FRONTIERS OF MATERIALS SYNTHESIS AND PROCESSING, 2019

• “The general digital twin mode for a product consists of three parts, which are the physical entities in physical space, the virtual models in virtual space, and the connected data that tie physical and virtual worlds. The physical entities are the real product that can be operated by the users.”. F. Tao, F. Sui, A. Liu, Q. Qi, M. Zhang, B. Song, Z. Guo, S.C.-Y. Lu, A.Y.C. Nee. Digital twin-driven product design framework. In: International Journal of Production Research, 2019

• “Digital twin is an integrated multi-physics, multiscale, and probabilistic simulation of a complex product and uses the best available physical models, sensor updates, etc., to mirror the life of its corresponding twin. “. F. Tao, J. Cheng,Q. Qi, M. Zhang, H. Zhang, F. Sui. Digital twin-driven product design, manufacturing and service with big data. In: INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY, 2018

• “the concept of using a digital copy of a physical system to perform real-time optimization is referred to as a DT”. F. Tao, Q. Qi, L. Wang, A.Y.C. Nee. Digital Twins and Cyber-Physical Systems toward Smart Manufacturing and Industry 4.0: Correlation and Comparison. In: Engineering, 2019

• “A digital twin (DT) is a digital representation of a real-world entity or system.”, “A digital twin is a virtual representation of a physical product or process, used to understand and predict their performance.”. L. Rauch, M. Pietrzyk. Digital twins as a modern approach to design of industrial processes. In: Journal of Machine Engineering, 2019

• “digital twins are virtual clones of real systems or subsystems.”. W. Kuehn. Digital twins for decision making in complex production and logistic enterprises. In: International Journal of Design and Nature and Ecodynamics, 2018

• ” A Digital Twin though tightly connects the physical system (e.g., one particular machine) with its computer model, so that the latter closely reflects the architecture, the dynamics and the actual state of this one particular system.”. K. Bruynseels, F. S. de Sio, J. van den Hoven. Digital Twins in Health Care: Ethical Implications of an Emerging Engineering Paradigm. In: FRONTIERS IN GENETICS, 2018

• “The term digital twins refers to the development of virtual models of processes, products or services that allow the simulation of system behavior and the early detection of problems before the real system exists.”. H.-D. Wuttke, K. Henke, R. Hutschenreuter. Digital Twins in Remote Labs. In: Cyber-physical Systems and Digital Twins, 2020

• “In a short, the digital twin technique deploys various sensors on the physical entities. By sensing the operational state of the physical world, the virtual model that is mutually mapped, mutually interacted and effectively collaborated with the physical entities in the cyberspace.”. Y. Shi, J. Xu, W. Du. Discussion on the New Operation Management Mode of Hydraulic Engineering Based on the Digital Twin Technique. In: Journal of Physics: Conference Series, 2019

• “The new technology, accessing to realistic models of the current state of the process and their own behaviors in interaction with their environment in the real world is called the “Digital Twin”. “Digital twin is an integrated multi-physics, multiscale and probabilistic simulation of a complex product and uses the best available physical models, sensor updates, etc. to mirror the life of its corresponding twin.”. J. Liu, H. Zhou, X. Liu, G. Tian, M. Wu, L. Cao, W. Wang. Dynamic Evaluation Method of Machining Process Planning Based on Digital Twin. In: IEEE Access, 2019

• “a “digital twin” is a virtual representation of a real world subject (person, software system, …) or a real world object (machine, component, part of the environment, …)”. M. Schluse, J. Rossmann. From simulation to experimentable digital twins: Simulation-based development and operation of complex technical systems. In: 2016 IEEE International Symposium on Systems Engineering (ISSE), 2016

• “digital twin is a digital replica of a physical object, device, system, place or person”. A. Fricke, H. Asche. Geospatial Database for the Generation of Multidimensional Virtual City Models Dedicated to Urban Analysis and Decision-Making. In: Computational Science and Its Applications ICCSA 2019, 2019

• “The term digital twin refers to a digital replica of physical assets, processes and systems that can be used in real-time for control and decision purposes.”. J. Vatn. Industry 4.0 and real-time synchronization of operation and maintenance. In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018, 2018

• “Generally, the term [Digital Twin] is used to describe two things: the administration shell of a CPS and simulation models.”. J. Reitz, M. Schluse, J. Rossmann. Industry 4.0 beyond the Factory: An Application to Forestry. In: Tagungsband des 4. Kongresses Montage Handhabung Industrieroboter, 2019

• “we define the Digital Twin of a physical object as the sum of all logically related data, i.e. engineering data and operational data, represented by a semantic data model.”. M. Kunath, H. Winkler. Integrating the Digital Twin of the manufacturing system into a decision support system for improving the order management process. In: Procedia CIRP, 2018

• “In this approach the term is used to describe a virtual representation based on AR-technology of a physical object which can or already exists in the real world.”. H. Pargmann, D. Euhausen, R. Faber. Intelligent big data processing for wind farm monitoring and analysis based on cloud-technologies and digital twins: A quantitative approach. In: 2018 IEEE 3rd International Conference on Cloud Computing and Big Data Analysis (ICCCBDA), 2018

• “The Digital Twin can be defined as an evolving profile of the history of current behaviour of a physical object or a process. That helps to optimize the performance of a production factory.”. M. Krajcovic, P. Grznar, M. Fusko, R. Skokan. Intelligent logistics for intelligent production systems. In: Communications - Scientific Letters of the University of Zilina, 2018

• “A DT is the virtual representation of a real technical asset, including its appearance, behavior, and interfaces.”. L. Atorf, J. Rossmann. Interactive Analysis and Visualization of Digital Twins in High-Dimensional State Spaces. In: 2018 15th International Conference on Control, Automation, Robotics and Vision, ICARCV 2018, 2018

• “an integrated multiphysics, multiscale simulation of a vehicle or system that uses the best available physical model, sensor updates, fleet history, to mirror the life of its corresponding flying twin”.. C. Steinmetz, A. Rettberg, F. G. C. Ribeiro, G. Schroeder, C. E. Pereira. Internet of Things Ontology for Digital Twin in Cyber Physical Systems. In: 2018 VIII Brazilian Symposium on Computing Systems Engineering (SBESC), 2018

• “The concept Digital Twin aims at giving a virtual representation of a physical entity that is as complete-as-possible.”. H. Zipper, F. Auris, A. Strahilov, M. Paul. Keeping the digital twin up-to-date - Process monitoring to identify changes in a plant. In: Proceedings of the IEEE International Conference on Industrial Technology, 2018

• “The vision of the digital twin itself includes more or less all information which could be useful in all – the current and subsequent – lifecycle phases”. I. Naplekov, I. Zheleznikov, D. Pashchenko, P. Kobysheva, A. Moskvitina, R. Mustafin, M. Gnutikova, A. Mullagalieva, P. Uzlov. Methods of computational modeling of coronary heart vessels for its digital twin. In: MATEC Web of Conferences, 2018

• “A digital twin of a production system is a multi-level digital layout that describes the product, processes and resources in the environment of their functioning”. N. Demkovich, E. Yablochnikov, G. Abaev. Multiscale modeling and simulation for industrial cyber-physical systems. In: 2018 IEEE Industrial Cyber-Physical Systems (ICPS), 2018

• “The digital twin is the virtual representation of a physical object or system across its life-cycle. It uses real-time data and other sources to enable learning, reasoning, and dynamically recalibrating for improved decision making.”. D. Preuveneers, W. Joosen, E. Ilie-Zudor. Robust Digital Twin Compositions for Industry 4.0 Smart Manufacturing Systems. In: Proceedings - IEEE International Enterprise Distributed Object Computing Workshop, EDOCW, 2018

• “Digital twin refers to a digital replica of physical assets, processes and systems that can be used for various purposes.”. H. Lee, T. Kim. Smart factory use case model based on digital twin. In: ICIC Express Letters, Part B: Applications, 2018

• “They are virtual representations of real systems not only including the physical 3D appearance but also its behaviour”. A. Ardanza, A. Moreno, Á. Segura, M. de la Cruz, D. Aguinaga. Sustainable and flexible industrial human machine interfaces to support adaptable applications in the Industry 4.0 paradigm. In: International Journal of Production Research, 2019

• “the exact mirror of the real system and its controlling part”. R. Beregi, Á. Szaller, B. Kádár. Synergy of multi-modelling for process control. In: IFAC-PapersOnLine, 2018

• “The Digital twin is a virtual representation of the physical product, a digital shadow that contains all the information and knowledge of it.”. G. Schroeder, C. Steinmetz, C. E. Pereira, I. Muller, N. Garcia, D. Espindola, R. Rodrigues. Visualising the digital twin using web services and augmented reality. In: 2016 IEEE 14th International Conference on Industrial Informatics (INDIN), 2016

• “Cyber-Physical Systems (CPSs) are formed by embedding the assets with computers, or microcontrollers, which run real-time decision-making algorithms over the data originating from the asset. These are known as the ‘Digital Twins’ of the assets, and form the backbone of social assets.”. K. Bakliwal, M. H. Dhada, A. S. Palau, A. K. Parlikad, B. K. Lad. A Multi Agent System architecture to implement Collaborative Learning for social industrial assets. In: IFAC-PapersOnLine, 2018

• “The basis […] builds a virtual representation of a product - called the digital twin or digital shadow.”. G. Schuh, M. Blum. Design of a data structure for the order processing as a basis for data analytics methods. In: 2016 Portland International Conference on Management of Engineering and Technology (PICMET), 2016

• “digital duplicate of the physical entity”. D. Shangguan, L. Chen, J. Ding. A hierarchical digital twin model framework for dynamic cyber-physical system design. In: ACM International Conference Proceeding Series, 2019

• “A virtual replica that mirrors the physical facility in near real-time”. E. La Grange. A roadmap for adopting a digital lifecycle approach to offshore oil and gas production. In: Proceedings of the Annual Offshore Technology Conference, 2018

• “The digital twin in essence is the both the representation of the physical system and the intelligence for controlling and/or modifying the production line”. S. J. Hatakeyama, D. W. Seal, D. Farr, S. C. Haase. An alternate view of the systems engineeringV in a model-based engineering environment. In: 2018 AIAA SPACE and Astronautics Forum and Exposition, 2018

• “The sum of data points can be referred as a digital twin of the physical feature.”. F. Yacob, D.Semere, E. Nordgren. Anomaly detection in Skin Model Shapes using machine learning classifiers. In: The International Journal of Advanced Manufacturing Technology, 2019

• “The Digital Thread and Digital Twin are interactive elements of the life cycle representation of the system. The Digital Twin is initiated from early descriptions/models of the airframe developed and preserved in the Digital Thread. […] Overall the configuration of the Digital Twin is controlled through the Digital Thread.”. E. M. Kraft. Approach to the development and application of a digital thread/digital twin authoritative truth source. In: 2018 Aviation Technology, Integration, and Operations Conference, 2018

• “Digital Twin - a digital replica of a physical asset that is updated so to continuously represent the state of the physical asset during its life cycle.”. J. Hlady, M. Glanzer, L. Fugate. Automated creation of the pipeline digital twin during construction - Improvement to construction quality and pipeline integrity. In: Proceedings of the Biennial International Pipeline Conference, IPC, 2018

• “a complete digital representation of the physical component, as well as test and validation data”. C. Mandolla, A. M. Petruzzelli, G. Percoco, A. Urbinati. Building a digital twin for additive manufacturing through the exploitation of blockchain: A case analysis of the aircraft industry. In: Computers in Industry, 2019

• “A concept of digital twin, which is a ultra-realistic virtual counterpart of a real-world object”. H. Park, A. Easwaran, S. Andalam. Challenges in Digital Twin Development for Cyber-Physical Production Systems. In: Cyber Physical Systems. Model-Based Design, 2019”

• “A DT is—from a structural, functional, and behavioural point-of-view—a one-to-one virtual representation of a real world artefact (such as a machine, a component, or objects from the environment) and comprises models of their “data” (geometry, structure, etc.), functionality (data processing, behaviour, etc.), and communication interfaces.”. M. Di Maio, G.-D. Kapos, N. Klusmann, L. Atorf, U. Dahmen, M. Schluse, J. Rossmann. Closed-loop systems engineering (close): integrating experimentable digital twins with the model-driven engineering process. In: 4th IEEE International Symposium on Systems Engineering, ISSE 2018 - Proceedings, 2018

• “A DT is a data structure suitable for use as a central data collection or connection point. It represents a dynamic digital image of, i.e., real production or of real products and continuously collects and records relevant data from the operation and over the product life cycle.”. F. Ströer, P. Sivasothy, K.-G. Faißt, H. Apostolov, T. Eickhoff, D. Bechev, G. Bulun, J. Seewig, M. Eigner, B. Sauer. Combined development and test of product-service systems in early product development stages for customized, availability-oriented business models in the capital goods industry. In: Procedia CIRP, 2018

• “In Digital Twin applications, a computational model of each asset is matched to its physical counterpart. The model is updated and maintained in a state matching its physical counterpart via operating history (load, displacement, temperature, etc.) that is measured on the asset, transmitted to and recorded in a database, and finally applied to the Digital Twin.”. W. V. Mars, J. D. Suter, M. Bauman. Computing Remaining Fatigue Life under Incrementally Updated Loading Histories. In: SAE Technical Papers, 2018”

• “The digital twin is a virtual model of a physical asset capable of fully monitoring its characteristics and functionalities during its entire lifecycle. It is an approach to manage all generated digital data of a component or system along its lifecycle and retrieve them as needed by simulation or optimization functions to adress any occurring challenges.”. B. A.Talkhestani, N. Jazdi, W. Schloegl, M. Weyrich. Consistency check to synchronize the Digital Twin of manufacturing automation based on anchor points. In: Procedia CIRP, 2018”

• “A digital twin refers to a digital replica of a business model [3] [4], e.g. with a physical product.”. K. Rambow-Hoeschele, A. Nagl, D. K. Harrison, B. M. Wood, K. Bozem, K. Braun, P. Hoch. Creation of a Digital Business Model Builder. In: 2018 IEEE International Conference on Engineering, Technology and Innovation, ICE/ITMC 2018 - Proceedings, 2018”

• “Generally, virtual models of physical objects are created digitally to simulate their behavior in realworld environments [10]. Thus, the digital twin is composed of three components, namely the physical entities in the physical world, the virtual models in the virtual world, and the connected data that tie the two worlds.”. E. Frontoni, J. Loncarski, R. Pierdicca, M. Bernardini, M. Sasso. Cyber Physical Systems for Industry 4.0: Towards Real Time Virtual Reality in Smart Manufacturing. In: Augmented Reality, Virtual Reality, and Computer Graphics, 2018”

• “a digital twin, which is a virtual model of the physical plant”. D. M. Tilbury. Cyber-Physical Manufacturing Systems. In: ANNUAL REVIEW OF CONTROL, ROBOTICS, AND AUTONOMOUS SYSTEMS, VOL 2, 2019

• “The concept of using a digital copy of the physical system to perform real-time optimization is often referred to as a Digital Twin.”; “The vision of the Digital Twin itself refers to a comprehensive physical and functional description of a component, product or system, which includes more or less all information which could be useful in the current and subsequent lifecycle phases.”. R. Bohlin, J. Hagmar, K. Bengtsson, L. Lindkvist, J. S. Carlson, R. Soderberg. DATA FLOW AND COMMUNICATION FRAMEWORK SUPPORTING DIGITAL TWIN FOR GEOMETRY ASSURANCE. In: PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2017, VOL 2, 2018”

• “a digital twin is a mimic of a real world asset displaying up to date information of what is currently happening”. J. M. Eyre, M. R. Lanyon-Hogg, T. J. Dodd, A. J. Lockwood, C. Freeman, R. W. Scott. Demonstration of an industrial framework for an implementation of a process digital twin, 2018

• “The phrase “digital twin” has been used […] to represent the joining of data with some form of a computer model of an asset, whether it be a component, process or system. The condition and performance of the asset can then be assessed in virtual space using the model capabilities.”. D. Renzi, D. Maniar, S. McNeill, C. Del Vecchio. Developing a digital twin for floating production systems integrity management. In: OTC Brasil 2017, 2017

• “A Digital Twin is a virtual model of a process, product or service to accelerate design, develop new opportunities and plan for the future by using simulation.”. B. Dawes, N. Meah, A. Kudryavtsev, R. Evans, M. Hunt, P. Tiller. Digital geometry to support a gas turbine digital twin. In: AIAA Scitech 2019 Forum, 2019

• “Digital representation of a real world entity or service”. C. Geselschap, G. Meskers, R. Van Dijk, I. Van Winsen. Digital twin - Engineering with the human factor in the loop. In: Proceedings of the Annual Offshore Technology Conference, 2019

• “Digital Twin can be defined as a replication of real physical production system in digital model, which are used for system optimization, monitoring, diagnostics and prognostics using integration of artificial intelligence, machine learning and software analytics with large volume of data from physical systems.”. Y. Liau, H. Lee, K. Ryu. Digital Twin concept for smart injection molding. In: 2017 5TH INTERNATIONAL CONFERENCE ON MECHANICAL ENGINEERING, MATERIALS SCIENCE AND CIVIL ENGINEERING, 2018

• “A digital twin is a virtual representation of an asset, used from early desing through building and operations, maintained and easily accessible throughout its lifecycle”. L. Pivano, D. T. Nguyen, K. B. Ludvigsen. Digital twin for drilling operations - Towards cloud-based operational planning. In: Proceedings of the Annual Offshore Technology Conference, 2019

• “Digital twin is a software model which is composed of 3D physical, mechanical, and electrical data along with detailed information about its assembly process and instructions on production.”. K. Vijayakumar, C. Dhanasekaran, R. Pugazhenthi, S. Sivaganesan. Digital twin for factory system simulation. In: International Journal of Recent Technology and Engineering, 2019

• “The digital twin is an integrated system with lowcost IoT sensors to gather system data, advanced data analytics to draw meaningful insights and predictive maintenance strategy based on the machine learning algorithm to reduce preventive maintenance cost. Overall the digital twin act as a digital replica of the field asset which is monitored and maintained based on actual sensor data from the physical field using machine learning.”. S. Bhowmik. Digital twin of subsea pipelines: Conceptual design integrating IoT, machine learning and data analytics. In: Proceedings of the Annual Offshore Technology Conference, 2019

• “A digital twin is a virtual prototype of a real physical product, product group, or process, the essence of which is to collect and reuse digital information.”. S. O. Kosenkov, V. Y. Turchaninov, I. S. Korovin, D. Y. Ivanov,. Digital Twin of the Oil Well, Based on Data Mining Technologies. In: 2ND INTERNATIONAL CONFERENCE ON MODELING, SIMULATION AND OPTIMIZATION TECHNOLOGIES AND APPLICATIONS (MSOTA 2018), 2018

• “Digital twin, which is to create high-fidelity virtual models for physical objects in digital way to simulate their behaviors[…].”. Q. Qi, F. Tao, Y. Zuo, D. Zhao. Digital Twin Service towards Smart Manufacturing. In: Procedia CIRP, 2018

• “The digital twin, conceived during the early concept phase (or retrofit to existing assets), draws together diverse data sources into an integrated format which can be managed and enriched as the asset progresses through its lifecycle.”. A. F. Tjønn. Digital twin through the life of a field. In: Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2018, ADIPEC 2018, 2019

• “a digital, real-time, in-context, operational mime of an asset, which connects the digital and real world representations towards actionable insights”. A. Bekker. Exploring the blue skies potential of digital twin technology for a polar supply and research vessel. In: Marine Design XIII, 2018

• “A digital twin is a digital representation of something that exists in the physical world.”. F. Laborie, O. C. Røed, G. Engdahl, A. Camp. Extracting value from data using an industrial data platform to provide a foundational digital twin. In: Proceedings of the Annual Offshore Technology Conference, 2019”

• “The Digital Twin is a virtual image of an asset, maintained throughout the lifecycle and should be easily accessible at any time”. T.-H. Stachowski, H. Kjeilen. Holistic ship design - How to utilise a digital twin in concept design through basic and detailed design. In: RINA, Royal Institution of Naval Architects - International Conference on Computer Applications in Shipbuilding, ICCAS 2017, 2017

• “Even though a Digital Twin is a complete model of its physical equivalent, the content of a Digital Twin is of course depending on its purpose.”. K. Wärmefjord, R. Söderberg, L. Lindkvist, B. Lindau, J. S. Carlson. Inspection data to support a Digital Twin for geometry assurance. In: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 2017

• “Virtual counterparts are commonly referenced by the term digital twin. Even though the term was defined as “an integrated multiphysics, multiscale, probabilistic simulation that uses the best available physical models, we equalize the model without simulation as the digital twin of the production system. The digital twin of the production system is composed by digital twins of the different components included within the production system,”. M. Bartelt, B. Kuhlenkoetter. Involving the Manufacturing System within its Planning Phase. In: 2018 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL ENGINEERING AND ENGINEERING MANAGEMENT (IEEE IEEM), 2018

• “[a]n integrated multiphysics, multiscale, probabilistic simulation of an as-built system, enabled by Digital Thread, that uses the best available models, sensor information, and input data to mirror and predict activities/performance over the life of its corresponding physical twin.”. T. D. West, M. Blackburn. Is Digital Thread/Digital Twin Affordable? A Systemic Assessment of the Cost of DoD’s Latest Manhattan Project. In: COMPLEX ADAPTIVE SYSTEMS CONFERENCE WITH THEME: ENGINEERING CYBER PHYSICAL SYSTEMS, CAS, 2017

• “digital twin is a complete virtual representation of a physical part or process”. A. Mayes, J. Heffernan, L. Jauriqui, R. Livings, E. Biedermann, J. C. Aldrin, B. R. Goodlet, S. Mazdiyasni. Process compensated resonance testing (PCRT) inversion for material characterization and digital twin calibration. In: AIP Conference Proceedings, 2019

• “A Digital Twin is usually seen as more powerful than a Digital Shadow, which accumulates data from a real system”. T. Delbruegger, J. Rossmann. Representing adaptation options in experimentable digital twins of production systems. In: INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING, 2019”

• “A digital twin is a dynamic virtual representation of a physical system that can be used for operational insight and life-cycle management”. M. Schirmann, M. Collette, J. Gose. Ship motion and fatigue damage estimation via a digital twin. In: Life-Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision - Proceedings of the 6th International Symposium on Life-Cycle Civil Engineering, IALCCE 2018, 2019”

• “A detailed digital model of the entire asset, which represents all relevant aspects of the asset”. D. J. Knezevic, H. Kang, P. Sharma, G. Malinowski, T. T. Nguyen. Structural integrity management of offshore structures via RB-FEA and fast full load mapping based digital twins. In: Proceedings of the International Offshore and Polar Engineering Conference, 2018

• “The digital twin is a virtual representation of an asset used from early design through building and operation, maintained and easily accessible throughout its lifecycle. The DT integrates real-time sensor data, inspection results, physics models and equipment performance data with advanced analytics for the entire asset to drive the data driven decision making process.”. P. Sharma, H. Hamedifar, A. Brown, R. Green. The dawn of the new age of the industrial internet and how it can radically transform the offshore oil and gas industry. In: Proceedings of the Annual Offshore Technology Conference, 2017

• “The interactive design and programming of the machining processes can be simulated virtually. Once this stage fulfills the design objectives and tolerances, the produced NC program is transferred to the physical machine, expecting that the interactive simulation results will match the actual results of the machine. If this happens, the virtual simulated machine is said to be a Digital Twin of the physical machine”. A. Moreno, G. Velez, A. ArdanzaI, Ã. Barandiaran, l. R. de Infante, R. Chopitea. Virtualisation process of a sheet metal punching machine within the Industry 4.0 vision. In: International Journal on Interactive Design and Manufacturing (IJIDeM), 2017__