Em Bortnik

Analyzing a Chi model of a turntable system using Spin, CADP, and Uppaal

Nowadays, due to increasing system complexity and growing competition and costs, industry makes high demands on powerful techniques used to design and analyze manufacturing systems. One of the most popular techniques to do performance analysis is simulation. However, simulation-based analysis cannot guarantee the correctness of a system, so it is less suitable for functional analysis. Our research focuses on examining other methods to do performance analysis and functional analysis, and trying to combine the two. One of the approaches is to translate a simulation model that is used for performance analysis to a model written in an input language of an existing verification tool. We translate a χ [D.A. van Beek, K.L. Man, M.A. Reniers, J.E. Rooda, R.R.H. Schiffelers, Syntax and Consistent Equation Semantics of Hybrid Chi, CS-Report 04-37, Eindhoven University of Technology, 2004] simulation model of a turntable system into models written in the input languages of the tools CADP [J.-C. Fernandez, H. Garavel, A. Kerbrat, L. Mounier, R. Mateescu, M. Sighireanu, CADP—a protocol validation and verification toolbox, in: Proceedings of the 8th Conference on Computer Aided Verification (CAV’96), Lecture Notes in Computer Science, vol. 1102, 1996, pp. 437–440], Spin [G.J. Holzmann, The SPIN Model Checker, Addison-Wesley, 2003] and Uppaal [K.G. Larsen, P. Pettersson, W.Yi, Uppaal in a nutshell, Int. J. Software Tools for Technology Transfer 1 (1–2) (1997) 134–152] and do a functional analysis with each of them. This allows us to evaluate the usefulness of these tools for the functional analysis of χ models. We compare the input formalisms, the expressiveness of the temporal logics, and the algorithmic techniques for model checking that are used in those tools.

Solving scheduling problems by untimed model checking: the clinical chemical analyser case study

In this paper, we show how scheduling problems can be modelled in untimed process algebra, by using special tick-actions. As a result, we can use efficient, distributed state space generators to solve scheduling problems. Also, we can use more flexible data specifications than timed model checkers usually provide. We propose a variant on breadth-first search, which visits the states per time slice between ticks. We applied our approach to find optimal schedules for test batches of a realistic clinical chemical analyser, which performs several kinds of tests on patient samples.

Model-based system analysis using Chi and Uppaal: An industrial case study

Abstract New methods and techniques are needed to reduce the integration and test effort (lead time, costs, resources) in the development of high-tech multi-disciplinary systems. To facilitate this effort reduction, a method called model-based integration and testing is being developed. The method allows to integrate formal and executable models of system components that are not yet physically realized with available realizations of other components. The combination of models and realizations is then used for early analysis of the integrated system by means of validation, verification, and testing. The analysis enables early detection and prevention of problems that would otherwise occur during real integration, resulting in a significant reduction of effort invested in the real integration and testing phases. This paper illustrates the application of the method to a realistic industrial case study, focusing on verification of the models obtained. We show how a system model has been developed for model-based integration and testing in the timed process algebra χ (Chi), and how certain behavioral properties of this model have been verified by the Uppaal model checker.