This paper presents algorithms for the automatic synthesis of real-time controllers by finding a winning strategy for certain games defined by the timed-automata of Alur and Dill. In such games, the outcome depends on the players' actions as well as on their timing. We believe that these results will pave the way for the application of program synthesis techniques to the construction of real-time embedded systems from their specifications.

On the synthesis of discrete controllers for timed systems

Static analysis of software with deductive methods is a highly dynamic field of research on the verge of becoming a mainstream technology in software engineering. It consists of a large portfolio of - mostly fully automated - analyses: formal verification, test generation, security analysis, visualization, and debugging. All of them are realized in the state-of-art deductive verification framework KeY. This book is the definitive guide to KeY that lets you explore the full potential of deductive software verification in practice. It contains the complete theory behind KeY for active researchers who want to understand it in depth or use it in their own work. But the book also features fully self-contained chapters on the Java Modeling Language and on Using KeY that require nothing else than familiarity with Java. All other chapters are accessible for graduate students (M.Sc. level and beyond). The KeY framework is free and open software, downloadable from the book companion website which contains also all code examples mentioned in this book.

Deductive Software Verification - The KeY Book

The premise of variability-intensive systems, specifically in software product line engineering, is the ability to produce a large family of different systems efficiently. Many such systems are critical. Thorough quality assurance techniques are thus required. Unfortunately, most quality assurance techniques were not designed with variability in mind. They work for single systems, and are too costly to apply to the whole system family. In this paper, we propose an efficient automata-based approach to linear time logic (LTL) model checking of variability-intensive systems. We build on earlier work in which we proposed featured transitions systems (FTSs), a compact mathematical model for representing the behaviors of a variability-intensive system. The FTS model checking algorithms verify all products of a family at once and pinpoint those that are faulty. This paper complements our earlier work, covering important theoretical aspects such as expressiveness and parallel composition as well as more practical things like vacuity detection and our logic feature LTL. Furthermore, we provide an in-depth treatment of the FTS model checking algorithm. Finally, we present SNIP, a new model checker for variability-intensive systems. The benchmarks conducted with SNIP confirm the speedups reported previously.

Featured Transition Systems: Foundations for Verifying Variability-Intensive Systems and Their Application to LTL Model Checking

The evolution of markets and customer requirements with highest level of precision, has been achieved created with technology and information systems, a new way of make the operations in the companies, and just the companies with the ability to adapt faster to technological innovations may remain on the market. The last industrial revolution, known as industry 4.0 perceives the operations as a holistic system, its represents a challenge that must be fulfilled and faced in order to achieve stability and permanence in the market, from the point of view of the world economies. In the organizational and business area all the operations must be linked to computer systems and management of information in the network, which causes greater efficiency in the flow. With this new perception of industry and the business, it involves different analytical tools that aim at bigger efficiency in the service to the consumers, resulting in a greater competitiveness in the market and making the differentiator. This work is one of the first surveys that provides an extensive analysis and review of 110 publications that appear from 1/01/12 to 20/02/17. The purpose of the study is to analyze categorically recent advances through qualitative and segmentation methods allowing to reveal trends and areas of opportunity in the industry sense of 4.0 in order to obtain research gaps that may be executed in organizational systems on the value chain. Another point is to be a reference in future research related to the categories selected in this study.

Industry 4.0 framework for management and operations: a review

Data aggregation mechanisms in the Internet of things

This work contributes to the field of coordination, in particular to Reo, by improving existing approaches to execute synchronisation models in three major ways. First, this work supports decoupled execution and lightweight reconfiguration. We developed a prototype Dreams engine to test our distributed protocol, using an actor library for the Scala language. Reconfiguration of a small part of the system is independent of the execution or behaviour of unrelated parts of the same system. Second, Dreams outperforms previous Reo engines by using constraint satisfaction techniques. In each round of the execution of the Dreams framework, descriptions of the behaviour of all building blocks are combined and a coordination pattern for the current round is chosen using constraint satisfaction techniques. This approach requiring less time than previous attempts that collect all patterns before selecting one. Third, our work improves scalability by identifying synchronous regions. We statically discover regions of the coordination layer that can execute independently, thus achieving a truly decoupled execution of connectors. Consequently, the constraint problem representing the behaviour at each round is smaller and more easily solved.

https://scholarlypublications.universiteitleiden.nl/access/item%3A2960679/view

Synchronous Coordination of Distributed Components

Modern software systems must support a high degree of variability to accommodate a wide range of requirements and operating conditions. This paper introduces the Abstract Behavioural Specification (ABS) language and tool suite, a comprehensive platform for developing and analysing highly adaptable distributed concurrent software systems. The ABS language has a hybrid functional and object- oriented core, and comes with extensions that support the development of systems that are adaptable to diversified requirements, yet capable to maintain a high level of trustworthiness. Using ABS, system variability is consistently traceable from the level of requirements engineering down to object behaviour. This facilitates temporal evolution, as changes to the required set of features of a system are automatically reflected by functional adaptation of the system's behaviour. The analysis capabilities of ABS stretch from debugging, observing and simulating to resource analysis of ABS models and help ensure that a system will remain dependable throughout its evolutionary lifetime. We report on the experience of using the ABS language and the ABS tool suite in an industrial case study.

The ABS tool suite: modelling, executing and analysing distributed adaptable object-oriented systems

Synchronous coordination systems, such as Reo, exchange data via indivisible actions, while distributed systems are typically asynchronous and assume that messages can be delayed or get lost. To combine these seemingly contradictory notions, we introduce the Dreams framework. Coordination patterns in Dreams are described using a synchronous model based on the Reo language, whereas global system behaviour is given by the runtime composition of autonomous actors communicating asynchronously. Dreams also exploits the use of actors in the composition of synchronous coordination patterns to allow communication whenever possible, increasing the scalability of the implementation.

/pdf/dreams-a-framework-for-distributed-synchronous-coordination-4wa0lra1ls.pdf

Dreams: a framework for distributed synchronous coordination

The HATS project aims at developing a model-centric methodology for the design, implementation and verification of highly configurable systems, such as software product lines, centred around the Abstract Behavioural Specification (ABS) modelling Language. This article describes the variability modelling features of the ABS Modelling framework. It consists of four languages, namely, μ TVL for describing feature models at a high level of abstraction, the Delta Modelling Language DML for describing variability of the ‘code' base in terms of delta modules, the Product Line Configuration Language CL for linking feature models and delta modules together and the Product Selection Language PSL for describing a specific product to extract from a product line. Both formal semantics and examples of each language are presented.

/pdf/variability-modelling-in-the-abs-language-30wp057kyf.pdf

José Proença

Papers

Synchronous Coordination of Distributed Components

The ABS tool suite: modelling, executing and analysing distributed adaptable object-oriented systems

Dreams: a framework for distributed synchronous coordination

Variability modelling in the ABS language

Channel-based coordination via constraint satisfaction