Collaborative Verification-Driven Engineering of Hybrid Systems

Hybrid systems with both discrete and continuous dynamics are an important model for real-world cyber-physical systems. The key challenge is to ensure their correct functioning w.r.t. safety requirements. Promising techniques to ensure safety seem to be model-driven engineering to develop hybrid systems in a well-defined and traceable manner, and formal verification to prove their correctness. Their combination forms the vision of verification-driven engineering. Often, hybrid systems are rather complex in that they require expertise from many domains (e.g., robotics, control systems, computer science, software engineering, and mechanical engineering). Moreover, despite the remarkable progress in automating formal verification of hybrid systems, the construction of proofs of complex systems often requires nontrivial human guidance, since hybrid systems verification tools solve undecidable problems. It is, thus, not uncommon for development and verification teams to consist of many players with diverse expertise. This paper introduces a verification-driven engineering toolset that extends our previous work on hybrid and arithmetic verification with tools for (i) graphical (UML) and textual modeling of hybrid systems, (ii) exchanging and comparing models and proofs, and (iii) managing verification tasks. This toolset makes it easier to tackle large-scale verification tasks

Model-based dependability analysis : state-of-the-art, challenges and future outlook

Abstract: Over the past two decades, the study of model-based dependability analysis has gathered significant research interest. Different approaches have been developed to automate and address various limitations of classical dependability techniques to contend with the increasing complexity and challenges of modern safety-critical system. Two leading paradigms have emerged, one which constructs predictive system failure models from component failure models compositionally using the topology of the system. The other utilizes design models - typically state automata - to explore system behaviour through fault injection. This paper reviews a number of prominent techniques under these two paradigms, and provides an insight into their working mechanism, applicability, strengths and challenges, as well as recent developments within these fields. We also discuss the emerging trends on integrated approaches and advanced analysis capabilities. Lastly, we outline the future outlook for model-based dependability analysis

Fluent Logic Workflow Analyser: A Tool for The Verification of Workflow Properties

In this paper we present the design and implementation, as well as a use case, of a tool for workflow analysis. The tool provides an assistant for the specification of properties of a workflow model. The specification language for property description is Fluent Linear Time Temporal Logic. Fluents provide an adequate flexibility for capturing properties of workflows. Both the model and the properties are encoded, in an automated way, as Labelled Transition Systems, and the analysis is reduced to model checking.Comment: In Proceedings LAFM 2013, arXiv:1401.056

Analysis and verification of an automatic document feeder

Modern copying machines are versatile and complex systems in which embedded software plays an essential role. The progress towards faster and more stable machines that can satisfy ever growing customers' needs, places strict requirements on the efficiency and quality of such software. In order to meet these requirements, the software should be well-designed and free of errors. Using modern formal verification techniques, software designs can be checked for errors and deadlocks so that their quality can be assessed and improved at an early stage of the development process. In this paper, we analyze the embedded software of an Automatic Document Feeder (ADF). ADFs are important components of copier machines. The ADF studied here is a prototype developed by Océ-Technologies B.V., a company that develops professional printing systems. We construct a model of the ADF in µcrl, a process algebra-based specification language, and express the system's requirements in the modal µ-calculus. Next, we use the µcrl and Cadp tool sets to check whether the system meets its requirements. This analysis reveals important errors in the ADF and we propose solutions to these problems. Also, we show that some requirements that engineers assumed to be valid, are too strict. We present slightly weaker versions of these requirements and show that these do hold. In this sense, in addition to finding errors in the ADF, our analysis also led to a better understanding of the behaviour the system