Formal Compositional Semantics for Yakindu Statecharts

Many of today’s safety-critical systems are reactive, embedded systems. Their internal behavior is usually represented by state-based models. Furthermore, as the tasks carried out by such systems are getting more and more complex, there is a strong need for compositional modeling languages. Such modeling formalisms start from the component-level and use composition to build the system-level model as a collection of simple modules. There are a number of solutions supporting the model-based development of safety-critical embedded systems. One of the popular open-source tools is Yakindu, a statechart editor with a rich language and code generation capabilities. However, Yakindu so far lacks support for compositional modeling. This paper proposes a formal compositional language tailored to the semantics of Yakindu statecharts. We propose precise semantics for the composition to facilitate formal analysis and precise code generation. Based on the formal basis laid out here, we plan to build a complete tool-chain for the design and verification of component- based reactive systems

Formalizing Cyber--Physical System Model Transformation via Abstract Interpretation

Model transformation tools assist system designers by reducing the labor--intensive task of creating and updating models of various aspects of systems, ensuring that modeling assumptions remain consistent across every model of a system, and identifying constraints on system design imposed by these modeling assumptions. We have proposed a model transformation approach based on abstract interpretation, a static program analysis technique. Abstract interpretation allows us to define transformations that are provably correct and specific. This work develops the foundations of this approach to model transformation. We define model transformation in terms of abstract interpretation and prove the soundness of our approach. Furthermore, we develop formalisms useful for encoding model properties. This work provides a methodology for relating models of different aspects of a system and for applying modeling techniques from one system domain, such as smart power grids, to other domains, such as water distribution networks.Comment: 8 pages, 4 figures; to appear in HASE 2019 proceeding

Enhancing Graphical Model-Based System Design: An Avionics Case Study

Graphical model-based system design is very appealing. However, there exist many different formalisms, with different semantics---as far as they do have well-defined semantics---and differing capabilities of the accompanying tools. In this paper, we present a case study from the avionics domain and report on the experiences in using different modeling languages and tools. The focus here is on the pragmatics of modeling, i. e., the practical process of building and inspecting graphical models. The underlying application is a high-lift ï¬ap system, which is highly safety-critical and served as a demonstrator within the Dependable Embedded Components and Systems (DECOS) project that explored the design of distributed dependable systems build on time-triggered architectures. Specifically, we compare a realization in the Safety Critical Application Development Environment (SCADE), a commercial tool from Esterel-Technologies, with a design in the Kiel Integrated Environment for Layout (KIEL), a research tool that allows to explore novel model handling paradigms. Hence we compare traditional graphical drag-and-drop WYSIWYG modeling with alternative, productivity enhancing approaches. We conclude with a brief outlook on future extensions which will tightly integrate with existing tools based on the Eclipse platform

Modeling views in the layered view model for XML using UML

In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources. Conversely, since the introduction of Extensible Markup Language (XML), it is fast emerging as the dominant standard for storing, describing, and interchanging data among various web and heterogeneous data sources. In combination with XML Schema, XML provides rich facilities for defining and constraining user-defined data semantics and properties, a feature that is unique to XML. In this context, it is interesting to investigate traditional database features, such as view models and view design techniques for XML. However, traditional view formalisms are strongly coupled to the data language and its syntax, thus it proves to be a difficult task to support views in the case of semi-structured data models. Therefore, in this paper we propose a Layered View Model (LVM) for XML with conceptual and schemata extensions. Here our work is three-fold; first we propose an approach to separate the implementation and conceptual aspects of the views that provides a clear separation of concerns, thus, allowing analysis and design of views to be separated from their implementation. Secondly, we define representations to express and construct these views at the conceptual level. Thirdly, we define a view transformation methodology for XML views in the LVM, which carries out automated transformation to a view schema and a view query expression in an appropriate query language. Also, to validate and apply the LVM concepts, methods and transformations developed, we propose a view-driven application development framework with the flexibility to develop web and database applications for XML, at varying levels of abstraction

Formal Model Engineering for Embedded Systems Using Real-Time Maude

This paper motivates why Real-Time Maude should be well suited to provide a formal semantics and formal analysis capabilities to modeling languages for embedded systems. One can then use the code generation facilities of the tools for the modeling languages to automatically synthesize Real-Time Maude verification models from design models, enabling a formal model engineering process that combines the convenience of modeling using an informal but intuitive modeling language with formal verification. We give a brief overview six fairly different modeling formalisms for which Real-Time Maude has provided the formal semantics and (possibly) formal analysis. These models include behavioral subsets of the avionics modeling standard AADL, Ptolemy II discrete-event models, two EMF-based timed model transformation systems, and a modeling language for handset software.Comment: In Proceedings AMMSE 2011, arXiv:1106.596