11 research outputs found

    OnTrack: Reflecting on domain specific formal methods for railway designs

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    OnTrack is a tool that supports workflows for railway verification that has been implemented using model driven engineering frameworks. Starting with graphical scheme plans and finishing with automatically generated formal models set-up for verification, OnTrack allows railway engineers to interact with verification procedures through encapsulating formal methods. OnTrack is grounded on a domain specification language (DSL) capturing scheme plans and supports generation of various formal models using model transformations. In this paper, we detail the role model driven engineering takes within OnTrack and reflect on the use of model driven engineering concepts for developing domain specific formal methods toolsets

    14th Conference on DATA ANALYSIS METHODS for Software Systems

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    DAMSS-2023 is the 14th International Conference on Data Analysis Methods for Software Systems, held in Druskininkai, Lithuania. Every year at the same venue and time. The exception was in 2020, when the world was gripped by the Covid-19 pandemic and the movement of people was severely restricted. After a year’s break, the conference was back on track, and the next conference was successful in achieving its primary goal of lively scientific communication. The conference focuses on live interaction among participants. For better efficiency of communication among participants, most of the presentations are poster presentations. This format has proven to be highly effective. However, we have several oral sections, too. The history of the conference dates back to 2009 when 16 papers were presented. It began as a workshop and has evolved into a well-known conference. The idea of such a workshop originated at the Institute of Mathematics and Informatics, now the Institute of Data Science and Digital Technologies of Vilnius University. The Lithuanian Academy of Sciences and the Lithuanian Computer Society supported this idea, which gained enthusiastic acceptance from both the Lithuanian and international scientific communities. This year’s conference features 84 presentations, with 137 registered participants from 11 countries. The conference serves as a gathering point for researchers from six Lithuanian universities, making it the main annual meeting for Lithuanian computer scientists. The primary aim of the conference is to showcase research conducted at Lithuanian and foreign universities in the fields of data science and software engineering. The annual organization of the conference facilitates the rapid exchange of new ideas within the scientific community. Seven IT companies supported the conference this year, indicating the relevance of the conference topics to the business sector. In addition, the conference is supported by the Lithuanian Research Council and the National Science and Technology Council (Taiwan, R. O. C.). The conference covers a wide range of topics, including Applied Mathematics, Artificial Intelligence, Big Data, Bioinformatics, Blockchain Technologies, Business Rules, Software Engineering, Cybersecurity, Data Science, Deep Learning, High-Performance Computing, Data Visualization, Machine Learning, Medical Informatics, Modelling Educational Data, Ontological Engineering, Optimization, Quantum Computing, Signal Processing. This book provides an overview of all presentations from the DAMSS-2023 conference

    A Formal Methodology for Engineering Heterogeneous Railway Signalling Systems

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    Ph. D. Thesis.Over the last few decades, the safety assurance of cyber-physical systems has become one of the biggest challenges in the field of model-based system engineering. The challenge arises from an immense complexity of cyber-physical systems which have deeply intertwined physical, software and network system aspects. With significant improvements in a wireless communication and microprocessor technologies, the railway domain has become one of the frontiers for deploying cyber-physical signalling systems. However, because of the safety-critical nature of railway signalling systems, the highest level of safety assurance is essential. This study attempts to address the challenge of guaranteeing the safety of cyber-physical railway signalling systems by proposing a development methodology based on formal methods. In particular, this study is concerned with the safety assurance of heterogeneous cyber-physical railway signalling systems, which have emerged by gradually replacing outdated signalling systems and integrating mainline with urban signalling systems. The main contribution of this work is a formal development methodology of railway signalling systems. The methodology is based on the Event-B modelling language, which provides an expressive modelling language, a stepwise model development and a proof-based model verification. At the core of the methodology is a generic communication-based railway signalling Event-B model, which can be further refined to capture specific heterogeneous or homogeneous railway signalling configurations. In order to make signalling modelling more systematic we developed communication and hybrid railway signalling modelling patterns. The proposed methodology and modelling patterns have been evaluated on two case studies. The evaluation shows that the methodology does provide a system-level railway signalling modelling and verification method. This is crucial for verifying the safety of cyber-physical systems, as safety is dependent on interactions between different subsystems. However, the study has also shown that automatic formal verification of hybrid systems is still a major challenge and must be addressed in the future work in order to make this methodology more practical.(EPSRC and Siemens Rail Automation

    Business optimization through automated signaling design

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    M.Ing. (Engineering Management)Abstract: Railway signaling has become pivotal in the development of railway systems over the years. There is a global demand for upgrading signaling systems for improved efficiency. Upgrading signaling systems requires new signaling designs and modifications to adjacent signaling systems. The purpose of this research is to compare manually produced designs with design automation by covering the framework of multiple aspects of railway signaling designs in view of business optimization using computer drawings, programming software language and management of signaling designs. The research focuses on design automation from the preliminary design stage to the detailed design stage with the intention of investigating and resolving a common project challenge of time management. Various autonomous methods are used to seek improvement on the detailed design phase of re-signaling projects. An analysis on the project’s duration, resources and review cycles is conducted to demonstrate the challenges that are faced during the design of a project. Signaling designs are sophisticated and crucial in an ever-changing railway environment. As a result, there is a demand for efficiency and knowledge within railway signaling to achieve successful completion project target dates. A quantitative approach is used to identify the gaps leading to delays and best practices are applied using a comparative analysis to remediate on any snags that may potentially extend the project duration. The results illustrate that the resources required when automating detailed designs are reduced by two thirds for cable plans and book of circuits and reduced by one third for source documents. Successively, the projects benefit with reduced organizational resources, reduced design durations and reduced design review cycles. This research concludes that software integration of the signaling designs due to the efficiency and innovation of the selected computer drawing software and programming software language such as AutoCAD required less resources for computer drawings that are generated using automation tools compared to computer drawings that are generated manually. The resources required when automating the generation of signaling detailed designs are reduced for cable plans, book of circuits and source documents. This means that the business is optimized by utilizing less resources and subsequently delays are reduced during the design stage

    A systematic approach to model-based engineering of cyber-physical systems of systems

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    PhD ThesisThis thesis describes and evaluates methods for the model-based engineering of Systems of Systems (SoSs) where constituents comprise both computational and physical elements typical of Cyber-Physical Systems (CPSs). Such Cyber-Physical Systems of Systems (CPSoSs) use sensors and actuators to link the digital and physical worlds, and are composed of operationally and managerially independent constituent systems that interact to deliver an emerging service on which reliance is placed. The engineering of CPSoSs requires a combination of techniques associated with both CPS engineering and SoS engineering. Model-based SoS engineering techniques address organisation and integration of diverse systems through the use of disciplined architectural frameworks and contractual modelling approaches. Advances in model-based CPS engineering address the additional challenges of integrating semantically heterogeneous models of discrete and continuous phenomena. This thesis combines these approaches to develop a coherent framework for the model-based engineering of CPSoSs. The proposed approach utilises architectural frameworks to aid in the development of rich abstract models of CPSoSs. This is accompanied by the specification of an automated transformation process to generate heterogeneous co-models based on the architectural description. Verification of the proposed engineering approach is undertaken by its application to a case study describing the control of trains over a section of rail network, in which the (cyber) behaviour of control infrastructure must be considered in conjunction with the (physical) dynamics of train movements. Using the proposed methods, the development of this CPSoS uses architectural descriptions to generate an executable model to enable the analysis of safety and efficiency implications of the implemented control logic. The utility of the approach is evaluated by consideration of the impact of the proposed techniques on advancing the suitability and maturity of baseline technologies for the engineering of CPSoS. It is concluded that the proposed architectural framework provides effective guidance for the production of rich architectural descriptions of CPSoSs, and that the conversion between architectural and executable models is viable for implementation in a suitable open tools framework

    Ingénierie de modèle pour la sécurité des systèmes critiques ferroviaires

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    Development and application of formal languages are a long-standing challenge within the computer science domain. One particular challenge is the acceptance of industry. This thesis presents some model-based methodologies for modelling and verification of the French railway interlocking systems (RIS). The first issue is the modellization of interlocking system by coloured Petri nets (CPNs). A generic and compact modelling framework is introduced, in which the interlocking rules are modelled in a hierarchical structure while the railway layout is modelled in a geographical perspective. Then, a modelling pattern is presented, which is a parameterized model respecting the French national rules. It is a reusable solution that can be applied in different stations. Then, an event-based concept is brought into the modelling process of low-level part of RIS to better describe internal interactions of relay-based logic. The second issue is the transformation of coloured Petri nets into B machines, which can help designers on the way from analysis to implementation. Firstly, a detailed mapping methodology from non-hierarchical CPNs to abstract B machine notations is presented. Then the hierarchy and the transition priority of CPNs are successively integrated into the mapping process, in order to enrich the adaptability of the transformation. This transformation is compatible with various types of colour sets and the transformed B machines can be automatically proved by Atelier B. All these works at different levels contribute towards a global safe analysis frameworkLe développement et l’application des langages formels sont un défi à long terme pour la science informatique. Un enjeu particulier est l’acceptation par l’industrie. Cette thèse présente une approche pour la modélisation et la vérification des postes d’aiguillage français. La première question est la modélisation du système d’enclenchement par les réseaux de Petri colorés (RdPC). Un cadre de modélisation générique et compact est introduit, dans lequel les règles d’enclenchement sont modélisées dans une structure hiérarchique, tandis que les installations sont modélisées dans une perspective géographique. Ensuite, un patron de modèle est présenté. C’est un modèle paramétré qui intègre les règles nationales françaises qui peut être appliquée pour différentes gares. Puis, un concept basé sur l’événement est présenté dans le processus de modélisation des parties basses des postes d’aiguillage. La deuxième question est la transformation des RdPCs en machines B, qui va aider les concepteurs sur la route de l’analyse à application. Tout d’abord, une méthodologie détaillée, s’appuyant sur une table de correspondance, du RdPCs non-hiérarchiques vers les notations B est présentée. Ensuite, la hiérarchie et la priorité des transitions du RdPC sont successivement intégrées dans le processus de mapping, afin d’enrichir les possibilités de types de modèles en entrées de la transformation. Les machines B produites par la transformation permettent la preuve automatique intégrale par l’Atelier B. L’ensemble de ces travaux, chacun à leur niveau, contribuent à renforcer l’efficacité d’un cadre global d’analyse sécuritair

    Development of a Formal Verification Methodology for B Specifications using PERF formal toolkit. Application to safety requirements of railway systems.

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    The design of complex systems involves several design models supporting different analysis techniques for validation and verification purposes. These activities lead to the definition of heterogeneous modelling languages and analysis techniques. In this setting, meeting certification standards becomes a key issue in system engineering. Reducing heterogeneity due to the presence of different modelling languages can be addressed by providing an integrated framework in which involved modelling languages and techniques are formalised. In such a framework, checking global requirements fulfilment on heterogeneous models of a complex critical system becomes possible in many cases. The work presented in this thesis addresses the problem of integrated verification of system design models in the context of transportation systems, in particular railway systems. It has been achieved in context of the B-PERFect project of RATP (Parisian Public Transport Operator and Maintainer) aiming at applying formal verification using the PERF approach on the integrated safety-critical models of embedded software related to railway domain expressed in a single unifying modelling language: High Level Languge (HLL). We also discuss integrated verification at the system level. The proposed method for verification of safety-critical software is a bottom-up approach, starting from the source code to the high-level specification. This work addresses the particular case of the B method. It presents a certified translation of B formal models to HLL models. The proposed approach uses Isabelle/HOL as a unified logical framework to describe the formal semantics and to formalise the transformation relation between both modelling languages. The developed Isabelle/HOL models are proved in order to guarantee the correctness of our translation process. Moreover, we have also used weakbisimulation relation to check semantic preservation after transformations. In this thesis, we also present the implementation of the defined transformation syntactic rules as the B2HLL tool. Moreover, we show the model animation process we set up to validate the B2HLL translator tool with respect to the formalised transformation rules we defined in Isabelle/HOL. This approach helps us to validate definitions, lemmas and theorems of our formalised specifications. We have used the B2HLL tool to translate multiple B models, and we also show that when models are translated into this unified modelling language, HLL, it becomes possible to handle verification of properties expressed across different models

    A reactive architecture for cloud-based system engineering

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    PhD ThesisSoftware system engineering is increasingly practised over globally distributed locations. Such a practise is termed as Global Software Development (GSD). GSD has become a business necessity mainly because of the scarcity of resources, cost, and the need to locate development closer to the customers. GSD is highly dependent on requirements management, but system requirements continuously change. Poorly managed change in requirements affects the overall cost, schedule and quality of GSD projects. It is particularly challenging to manage and trace such changes, and hence we require a rigorous requirement change management (RCM) process. RCM is not trivial in collocated software development; and with the presence of geographical, cultural, social and temporal factors, it makes RCM profoundly difficult for GSD. Existing RCM methods do not take into consideration these issues faced in GSD. Considering the state-of-the-art in RCM, design and analysis of architecture, and cloud accountability, this work contributes: 1. an alternative and novel mechanism for effective information and knowledge-sharing towards RCM and traceability. 2. a novel methodology for the design and analysis of small-to-medium size cloud-based systems, with a particular focus on the trade-off of quality attributes. 3. a dependable framework that facilitates the RCM and traceability method for cloud-based system engineering. 4. a novel methodology for assuring cloud accountability in terms of dependability. 5. a cloud-based framework to facilitate the cloud accountability methodology. The results show a traceable RCM linkage between system engineering processes and stakeholder requirements for cloud-based GSD projects, which is better than existing approaches. Also, the results show an improved dependability assurance of systems interfacing with the unpredictable cloud environment. We reach the conclusion that RCM with a clear focus on traceability, which is then facilitated by a dependable framework, improves the chance of developing a cloud-based GSD project successfully

    Safety and Reliability - Safe Societies in a Changing World

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    The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen
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