729 research outputs found
Model the System from Adversary Viewpoint: Threats Identification and Modeling
Security attacks are hard to understand, often expressed with unfriendly and
limited details, making it difficult for security experts and for security
analysts to create intelligible security specifications. For instance, to
explain Why (attack objective), What (i.e., system assets, goals, etc.), and
How (attack method), adversary achieved his attack goals. We introduce in this
paper a security attack meta-model for our SysML-Sec framework, developed to
improve the threat identification and modeling through the explicit
representation of security concerns with knowledge representation techniques.
Our proposed meta-model enables the specification of these concerns through
ontological concepts which define the semantics of the security artifacts and
introduced using SysML-Sec diagrams. This meta-model also enables representing
the relationships that tie several such concepts together. This representation
is then used for reasoning about the knowledge introduced by system designers
as well as security experts through the graphical environment of the SysML-Sec
framework.Comment: In Proceedings AIDP 2014, arXiv:1410.322
A Case Study in Formal System Engineering with SysML
International audienceIn the development of complex critical systems, an important source of errors is the misinterpretation of system requirements allocated to the software, due to inadequate communication between system engineering teams and software teams. In response, organizations that develop such systems are searching for solutions allowing formal system engineering and system to software bridging, based on standard languages like SysML. As part of this effort, we have defined a formal profile for SysML (OMEGA SysML) and we have built a simulation and verification toolbox for this profile (IFx). This paper reports on the experience of modelling and validating an industry-grade system, the Solar Generation System (SGS) of the Automated Transfer Vehicle (ATV) built by Astrium, using IFx-OMEGA. The experience reveals what can currently be expected from such an approach and what are the weak points that should be addressed by future research and development
A Model-Based Approach To System-Of-Systems Engineering Via The Systems Modeling Language
In the field of Systems Engineering, a movement is underway to capture the aspects of a system in a centralized model format instead of various documents. This is the basis of Model Based Systems Engineering (MBSE). In order to better formalize this change, the Systems Modeling Language (SysML) was developed to characterize an ontology for MBSE. Despite the growth of both MBSE practices and SysML tools, they have yet to be rigorously analyzed as to their applicability to the field of System-of-Systems (SoS). This thesis applies SysML to a methodology for System-of-Systems Engineering (SoSE) known as the Wave Model, which focuses on an iterative approach to SoS development. Each applicable step in the Wave Model is performed within SysML. Three different SoS types - directed, acknowledged, and collaborative - are studied within the domain of a distrubuted sensor management problem. As each SoS is established, evaluated, and updated, the applicability of SysML to each step is discussed. It is found that SysML is capable of defining, analyzing, and evolving a SoS via the processes described in the Wave Model. SysML excels at strictly defining and organizing the elements and features of a SoS while requiring more development in the analysis portions of the SoSE process
Clafer: Lightweight Modeling of Structure, Behaviour, and Variability
Embedded software is growing fast in size and complexity, leading to intimate
mixture of complex architectures and complex control. Consequently, software
specification requires modeling both structures and behaviour of systems.
Unfortunately, existing languages do not integrate these aspects well, usually
prioritizing one of them. It is common to develop a separate language for each
of these facets. In this paper, we contribute Clafer: a small language that
attempts to tackle this challenge. It combines rich structural modeling with
state of the art behavioural formalisms. We are not aware of any other modeling
language that seamlessly combines these facets common to system and software
modeling. We show how Clafer, in a single unified syntax and semantics, allows
capturing feature models (variability), component models, discrete control
models (automata) and variability encompassing all these aspects. The language
is built on top of first order logic with quantifiers over basic entities (for
modeling structures) combined with linear temporal logic (for modeling
behaviour). On top of this semantic foundation we build a simple but expressive
syntax, enriched with carefully selected syntactic expansions that cover
hierarchical modeling, associations, automata, scenarios, and Dwyer's property
patterns. We evaluate Clafer using a power window case study, and comparing it
against other notations that substantially overlap with its scope (SysML, AADL,
Temporal OCL and Live Sequence Charts), discussing benefits and perils of using
a single notation for the purpose
Contracts and Behavioral Patterns for SoS: The EU IP DANSE approach
This paper presents some of the results of the first year of DANSE, one of
the first EU IP projects dedicated to SoS. Concretely, we offer a tool chain
that allows to specify SoS and SoS requirements at high level, and analyse them
using powerful toolsets coming from the formal verification area. At the high
level, we use UPDM, the system model provided by the british army as well as a
new type of contract based on behavioral patterns. At low level, we rely on a
powerful simulation toolset combined with recent advances from the area of
statistical model checking. The approach has been applied to a case study
developed at EADS Innovation Works.Comment: In Proceedings AiSoS 2013, arXiv:1311.319
An Approach Combining Simulation and Verification for SysML using SystemC and Uppaal
International audienceEnsuring the correction of heterogeneous and complex systems is an essential stage in the process of engineering systems.In this paper we propose a methodology to verify and validate complex systems specified with SysML language using a combination of the two techniques of simulation and verification. We translate SysML specifications into SystemC models to validate the designed systems by simulation, then we propose to verify the derived SystemC models by using the Uppaal model checker. A case study is presented to demonstrate the effectiveness of our approach
Mapping SysML to modelica to validate wireless sensor networks non-functional requirements
International audienceWireless Sensor Networks (WSN) have registered a large success in the scientific and industrial communities for their broad application domains. Furthermore, the WSN specification is a complex task considering to their distributed and embedded nature and the strong interactions between their hardware and software parts. Moreover, most of approaches use semi-formal methods to design systems and generally simulation to validate their properties in order to produce models without errors and conform to the system specifications. In this context, we propose a Model Driven Architecture (MDA) approach to improve the verification of the WSN properties. This approach combines the advantages of the System Modeling Language (SysML) and the Modelica language which promote the reusability and improve the development process. In this work, we specify a model transformation from SysML static, dynamic and requirement diagrams to their corresponding elements in Modelica. Thanks to the SysML requirement diagram which is transformed into Modelica properties (constraints), we propose a technique using dynamic tests to verify WSN properties. We have used the Topcased platform to implement our approach 1 and chosen a crossroads monitoring system which is based on wireless sensors to illustrate it. Besides, we have verified and validated some wireless sensors properties of the studied system
A Framework for Executable Systems Modeling
Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation.
In response to these challenges, a number of auxiliary standards have been offered by the Object Management Group (OMG); most pertinent here are the foundational UML subset (fUML), Action language for fUML (Alf), and the UML profile for Modeling and Analysis of Real Time and Embedded Systems (MARTE). However, there remains a lack of a similar treatment of SysML tailored towards precise and formal modeling in the systems engineering domain. This work addresses this gap by offering refined semantics for SysML akin to fUML and MARTE standards, aimed at primarily supporting the development of time based simulation models typically applied for model verification and validation in systems engineering.
The result of this work offers an Executable Systems Modeling Language (ESysML) and a prototype modeling tool that serves as an implementation test bed for the ESysML language. Additionally a model development process is offered to guide user appropriation of the provided framework for model building
Semantics of trace relations in requirements models for consistency checking and inferencing
Requirements traceability is the ability to relate requirements back to stakeholders and forward to corresponding design artifacts, code, and test cases. Although considerable research has been devoted to relating requirements in both forward and backward directions, less attention has been paid to relating requirements with other requirements. Relations between requirements influence a number of activities during software development such as consistency checking and change management. In most approaches and tools, there is a lack of precise definition of requirements relations. In this respect, deficient results may be produced. In this paper, we aim at formal definitions of the relation types in order to enable reasoning about requirements relations. We give a requirements metamodel with commonly used relation types. The semantics of the relations is provided with a formalization in first-order logic. We use the formalization for consistency checking of relations and for inferring new relations. A tool has been built to support both reasoning activities. We illustrate our approach in an example which shows that the formal semantics of relation types enables new relations to be inferred and contradicting relations in requirements documents to be determined. The application of requirements reasoning based on formal semantics resolves many of the deficiencies observed in other approaches. Our tool supports better understanding of dependencies between requirements
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