Combining SysML and Model Transformations to Support Systems Engineering Analysis

As modern systems become increasingly complex, there is a growing need to support the systems engineering process with a variety of formal models, such that the team of experts involved in the process can express and share knowledge precisely, succinctly and unambiguously. However, creating such formal models can be expensive and time-consuming, making a broad exploration of different system architectures cost-prohibitive. In this paper, we investigate an approach for reducing such costs and hence enabling broader architecture space exploration through the use of model transformations. Specifically, a method is presented for verifying design alternatives with respect to design requirements through automated generation of analyses from formal models of the systems engineering problem. Formal models are used to express the structure of design alternatives, the system requirements, and experiments to verify the requirements as well as the relationships between the models. These formal models are all represented in a common modeling language, the Object Management Group’s Systems Modeling Language (OMG SysMLTM). To then translate descriptive models of system alternatives into a set of corresponding analysis models, a model transformation approach is used to combine knowledge from the experiment models with knowledge from reusable model libraries. This set of analysis models is subsequently transformed into executable simulations, which are used to guide the search for suitable system alternatives. To facilitate performing this search using commercially available optimization tools, the analyses are represented using the General Algebraic Modeling System (GAMS). The approach is demonstrated on the design of a hydraulic subsystem for a log splitter

Towards the Model-Driven Engineering of Secure yet Safe Embedded Systems

We introduce SysML-Sec, a SysML-based Model-Driven Engineering environment aimed at fostering the collaboration between system designers and security experts at all methodological stages of the development of an embedded system. A central issue in the design of an embedded system is the definition of the hardware/software partitioning of the architecture of the system, which should take place as early as possible. SysML-Sec aims to extend the relevance of this analysis through the integration of security requirements and threats. In particular, we propose an agile methodology whose aim is to assess early on the impact of the security requirements and of the security mechanisms designed to satisfy them over the safety of the system. Security concerns are captured in a component-centric manner through existing SysML diagrams with only minimal extensions. After the requirements captured are derived into security and cryptographic mechanisms, security properties can be formally verified over this design. To perform the latter, model transformation techniques are implemented in the SysML-Sec toolchain in order to derive a ProVerif specification from the SysML models. An automotive firmware flashing procedure serves as a guiding example throughout our presentation.Comment: In Proceedings GraMSec 2014, arXiv:1404.163

Using domain specific languages to capture design knowledge for model-based systems engineering

Design synthesis is a fundamental engineering task that involves the creation of structure from a desired functional specification; it involves both creating a system topology as well as sizing the system's components. Although the use of computer tools is common throughout the design process, design synthesis is often a task left to the designer. At the synthesis stage of the design process, designers have an extensive choice of design alternatives that need to be considered and evaluated. Designers can benefit from computational synthesis methods in the creative phase of the design process. Recent increases in computational power allow automated synthesis methods for rapidly generating a large number of design solutions. Combining an automated synthesis method with an evaluation framework allows for a more thorough exploration of the design space as well as for a reduction of the time and cost needed to design a system. To facilitate computational synthesis, knowledge about feasible system configurations must be captured. Since it is difficult to capture such synthesis knowledge about any possible system, a design domain must be chosen. In this thesis, the design domain is hydraulic systems. In this thesis, Model-Driven Software Development concepts are leveraged to create a framework to automate the synthesis of hydraulic systems will be presented and demonstrated. This includes the presentation of a domain specific language to describe the function and structure of hydraulic systems as well as a framework for synthesizing hydraulic systems using graph grammars to generate system topologies. Also, a method using graph grammars for generating analysis models from the described structural system representations is presented. This approach fits in the context of Model-Based Systems Engineering where a variety of formal models are used to represent knowledge about a system. It uses the Systems Modeling Language developed by The Object Management Group (OMG SysML™) as a unifying language for model definition.M.S.Committee Chair: Paredis, Chris; Committee Member: McGinnis, Leon; Committee Member: Schaefer, Dir

Towards an Integrated Conceptual Design Evaluation of Mechatronic Systems: The SysDICE Approach

National audienceMechatronic systems play a significant role in different types of industry, especially in trans- portation, aerospace, automotive and manufacturing. Although their multidisciplinary nature provides enormous functionalities, it is still one of the substantial challenges which frequently impede their design process. Notably, the conceptual design phase aggregates various engi- neering disciplines, project and business management fields, where different methods, modeling languages and software tools are applied. Therefore, an integrated environment is required to intimately engage the different domains together. This paper outlines a model-based research approach for an integrated conceptual design evaluation of mechatronic systems using SysML. Particularly, the state of the art is highlighted, most important challenges, remaining problems in this field and a novel solution is proposed, named SysDICE, combining model based system engineering and artificial intelligence techniques to support for achieving efficient design

Combining mathematical programming and SysML for component sizing as applied to hydraulic systems

In this research, the focus is on improving a designer's capability to determine near-optimal sizes of components for a given system architecture. Component sizing is a hard problem to solve because of the presence of competing objectives, requirements from multiple disciplines, and the need for finding a solution quickly for the architecture being considered. In current approaches, designers rely on heuristics and iterate over the multiple objectives and requirements until a satisfactory solution is found. To improve on this state of practice, this research introduces advances in the following two areas: a.) Formulating a component sizing problem in a manner that is convenient to designers and b.) Solving the component sizing problem in an efficient manner so that all of the imposed requirements are satisfied simultaneously and the solution obtained is mathematically optimal. In particular, an acausal, algebraic, equation-based, declarative modeling approach is taken to solve component sizing problems efficiently. This is because global optimization algorithms exist for algebraic models and the computation time is considerably less as compared to the optimization of dynamic simulations. In this thesis, the mathematical programming language known as GAMS (General Algebraic Modeling System) and its associated global optimization solvers are used to solve component sizing problems efficiently. Mathematical programming languages such as GAMS are not convenient for formulating component sizing problems and therefore the Systems Modeling Language developed by the Object Management Group (OMG SysML ) is used to formally capture and organize models related to component sizing into libraries that can be reused to compose new models quickly by connecting them together. Model-transformations are then used to generate low-level mathematical programming models in GAMS that can be solved using commercial off-the-shelf solvers such as BARON (Branch and Reduce Optimization Navigator) to determine the component sizes that satisfy the requirements and objectives imposed on the system. This framework is illustrated by applying it to an example application for sizing a hydraulic log splitter.M.S.Committee Co-Chair: Paredis, Chris ; Committee Co-Chair: Schaefer, Dirk; Committee Member: Goel, Asho

Integrating Analysis Into a Warehouse Design Workflow

Supply chain analyses, including those related to material handling systems, are typically purpose-built to answer specific questions and therefore have many different implementations depending on the question, the instance data, and the solver. The purpose-built nature of these models makes it difficult to integrate them into an iterative design workflow. Despite the myriad analysis implementations, the fundamental structure of these systems and their problem domain remains unchanged, suggesting that perhaps analyses could be automatically generated on demand, given an appropriate specification of the particular system to be analyzed. We apply model-based systems engineering (MBSE) methodologies to explore this possibility in the context of functional warehouse design

SYSML4TA: A SysML Profile for Consistent Tolerance Analysis in a Manufacturing System Case Application

Tolerance analysis is a key engineering task that is usually supported by domain-specific analysis models and tools that are generally not connected to the system functionality. The model-based system engineering (MBSE) approach is a potential solution to this limitation, but it has not yet been deeply explored in this type of mechanical analysis, for which some problems need to be explored. One of these issues is the capacity of languages such as SysML to describe solution principles based on active surfaces that participate in functionality and are present for tolerance analysis. Thus, this study explored the possibilities that enable SysML to represent these geometries and their mathematical relationships based on Topologically and Technologically Related Surfaces (TTRS) theory and aligned with Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, the capacity of SysML to assure the consistency of tolerance analysis models is also explored, due to the limitations identified in analysis languages like Modelica. In this context, this paper presents a SysML profile for tolerance analysis modeling (SysML4TA), containing domain-specific semantics (concepts and constraints) to assure the completeness of the analysis models and consistency between the different models considered in the integrated model of the system. Finally, a case study applied to a manufacturing context is presented to validate the capacity of SysML to solve the identified problems.La herencia reconstruida. Crecimiento agrario y transformaciones del paisaje tras las conquistas de al-Andalus (siglos XII-XV

Formal methods for a system of systems analysis framework applied to traffic management

Formal methods for systems and system of systems engineering (SoSE) can bring precision to architecting and design, and increased trustworthiness in verification; but they require the use of formal languages that are not broadly comprehensible to the various stakeholders. The evolution of Model Based Systems Engineering (MBSE) using the Systems Modeling Language (SysML) lies in a middle ground between legacy document-based SoSE and formal methods. SysML is a graphical language but not a formal language. Initiatives in the Object Management Group (OMG), such as the development of the Foundational Unified Modeling Language (fUML) seek to bring precise semantics to object-oriented modeling languages. Following the philosophy of fUML, we offer a framework for associating precise semantics with Unified Modeling Language (UML) and SysML models essential for SoSE architecting and design. Straightforward methods are prescribed to develop the essential models and to create semantic transformations between them. Matrix representations can be used to perform analyses that are concordant with the system of UML or SysML models that represent the system or SoS. The framework and methods developed in this paper are applied to a Traffic Management system of systems (TMSoS) that has been a subject of research presented at previous IEEE SoSE conferences

Flexible Views for View-based Model-driven Development

Modern software development faces the problem of fragmentation of information across heterogeneous artefacts in different modelling and programming languages. In this dissertation, the Vitruvius approach for view-based engineering is presented. Flexible views offer a compact definition of user-specific views on software systems, and can be defined the novel ModelJoin language. The process is supported by a change metamodel for metamodel evolution and change impact analysis