In this paper, we propose a method for the automatic construction of an abstract state graph of a... more In this paper, we propose a method for the automatic construction of an abstract state graph of an arbitrary system using the Pvs theorem prover.
A Real-Time Profile for UML and How to Adapt It to SDL
Lecture Notes in Computer Science, 2003
ABSTRACT This paper presents work of the IST project OMEGA, where we have defined a UML profile f... more ABSTRACT This paper presents work of the IST project OMEGA, where we have defined a UML profile for real-time that is compatible with the Profile for Performance, Scheduling and Real-time recently accepted at OMG. In contrast to this OMG profile, we put emphasis on semantics and on its use in the context of timed analysis of real-time embedded systems. The defined profile is compatible with the time concepts existing in SDL, and we show how we can also adapt these notations to SDL and MSC, which do not yet have a notation for this purpose.
We present a technique and a tool for model-checking operational UML models based on a mapping of... more We present a technique and a tool for model-checking operational UML models based on a mapping of object oriented UML models into a framework of communicating extended timed automata -in the IF format -and the use of the existing model-checking and simulation tools for this format. We take into account most of the structural and behavioral characteristics of classes and their interplay and tackle issues like the combination of operations, state machines, inheritance and polymorphism, with a particular semantic profile for communication and concurrency. The UML dialect considered here, also includes a set of extensions for expressing timing. Our approach is implemented by a tool importing UML models via an XMI repository, and thus supporting several commercial and non-commercial UML editors. For user friendly interactive simulation, an interface has been built, presenting feedback to the user in terms of the original UML model. Model-checking and model exploration can be done by reusing the existing IF state-of-the-art validation environment.
Innovations in Systems and Software Engineering, 2008
This paper presents a case study in UML-based modeling and validation of the intricate timing asp... more This paper presents a case study in UML-based modeling and validation of the intricate timing aspects arising in a small but complex component of the airborne Medium-Altitude Reconnaissance System produced by the Netherlands National Aerospace Laboratory. The purpose is to show how automata-based timing analysis and verification tools can be used by field engineers for solving isolated hard points in a complex real-time design, even if the press-button verification of entire systems remains a remote goal. We claim that the accessibility of such tools is largely improved by the use of an UML profile with intuitive features for modeling timing and related properties.
A tool for symbolic program verification and abstraction
Lecture Notes in Computer Science, 1993
We give the description of a verification tool taking boolean programs of guarded commandsas inpu... more We give the description of a verification tool taking boolean programs of guarded commandsas input; internal representation of programs are sets of Binary Decision Diagrams(BDD) (one for each guarded command). It allows to construct an abstract program of thesame form obtained using an abstraction relation given by a boolean expression on "concrete"and "abstract" variables. The tool allows the verification of
ABSTRACT This paper presents an overview on the IF toolset which is an environment for modelling ... more ABSTRACT This paper presents an overview on the IF toolset which is an environment for modelling and validation of heterogeneous real-time systems. The toolset is built upon a rich formalism, the IF notation, allowing structured automata-based system representations. Moreover, the IF notation is expressive enough to support real-time primitives and extensions of high-level modelling languages such as SDL and UML by means of structure preserving mappings. The core part of the IF toolset consists of a syntactic transformation component and an open exploration platform. The syntactic transformation component provides language level access to IF descriptions and has been used to implement static analysis and optimisation techniques. The exploration platform gives access to the graph of possible executions. It has been connected to different state-of-the-art model-checking and test-case generation tools. A methodology for the use of the toolset is presented at hand of a case study concerning the Ariane-5 Flight Program for which both an SDL and a UML model have been validated.
Controlling concurrent systems to impose some global invariant, is an undecidable problem. One ca... more Controlling concurrent systems to impose some global invariant, is an undecidable problem. One can gain decidability at the expense of reducing concurrency. Even under this flexible design assumption, the synthesis problem remains highly intractable. One practical method for designing controllers is based on checking knowledge properties upon which the processes can make their decisions whether to allow or block transitions. A major deficiency of this synthesis method is in calculating the knowledge based on the given system that we want to control, and not on the resulted system. The original system has less knowledge, and as a result, we may introduce far more synchronization than needed. In this paper we show techniques to reduce this overhead.
IF: A Validation Environment for Timed Asynchronous Systems
Lecture Notes in Computer Science, 2000
Formal validation of distributed systems relies on several specification formalisms (such as the ... more Formal validation of distributed systems relies on several specification formalisms (such as the international standards lotos [15] or sdl [16]), and it requires different kinds of tools to cover the whole development process. Presently, a wide range of tools are available, either ...
We present work of a project for the improvement of a speci cation/validation toolbox integrating... more We present work of a project for the improvement of a speci cation/validation toolbox integrating a commercial toolset Objectgeode and di erent validation tools such as the veri cation tool cadp and the test sequence generator tgv.
Abstract. In this paper we propose some extensions necessary to en-able the specification and des... more Abstract. In this paper we propose some extensions necessary to en-able the specification and description language Sdl to become a more appropriate formalism for the design of real-time and embedded systems. The extensions we envisage concern both roles of Sdl: first, in ...
Modeling and Validation of a Software Architecture for the Ariane-5 Launcher
Lecture Notes in Computer Science, 2006
... In this section, we discuss briefly the concepts and we give an example of how they are put t... more ... In this section, we discuss briefly the concepts and we give an example of how they are put to work in the Ariane-5 model. ... An anomaly on the Vulcain ignition corresponds, in our modeling of the en-vironment, to a Valve object entering the Failed Open state. ...
What are the limits of model checking methods for the verification of real life protocols?
Lecture Notes in Computer Science, 1990
... some properties assume that all messages sent by some process are distinguishable, which requ... more ... some properties assume that all messages sent by some process are distinguishable, which requires an infinite set of message identifications if infinite execution sequences ... procedure, that effectively blocks all further communications in the affected group of stations ...
Spin [9] is a model checker for the verification of distributed systems software. The tool is fre... more Spin [9] is a model checker for the verification of distributed systems software. The tool is freely distributed, and often described as one of the most widely used verification systems. The Advanced Spin Tutorial is a sequel to [7] and is targeted towards intermediate to ...
In this paper, we propose a method for the automatic construction of an abstract state graph of a... more In this paper, we propose a method for the automatic construction of an abstract state graph of an arbitrary system using the Pvs theorem prover.
A Real-Time Profile for UML and How to Adapt It to SDL
Lecture Notes in Computer Science, 2003
ABSTRACT This paper presents work of the IST project OMEGA, where we have defined a UML profile f... more ABSTRACT This paper presents work of the IST project OMEGA, where we have defined a UML profile for real-time that is compatible with the Profile for Performance, Scheduling and Real-time recently accepted at OMG. In contrast to this OMG profile, we put emphasis on semantics and on its use in the context of timed analysis of real-time embedded systems. The defined profile is compatible with the time concepts existing in SDL, and we show how we can also adapt these notations to SDL and MSC, which do not yet have a notation for this purpose.
We present a technique and a tool for model-checking operational UML models based on a mapping of... more We present a technique and a tool for model-checking operational UML models based on a mapping of object oriented UML models into a framework of communicating extended timed automata -in the IF format -and the use of the existing model-checking and simulation tools for this format. We take into account most of the structural and behavioral characteristics of classes and their interplay and tackle issues like the combination of operations, state machines, inheritance and polymorphism, with a particular semantic profile for communication and concurrency. The UML dialect considered here, also includes a set of extensions for expressing timing. Our approach is implemented by a tool importing UML models via an XMI repository, and thus supporting several commercial and non-commercial UML editors. For user friendly interactive simulation, an interface has been built, presenting feedback to the user in terms of the original UML model. Model-checking and model exploration can be done by reusing the existing IF state-of-the-art validation environment.
Innovations in Systems and Software Engineering, 2008
This paper presents a case study in UML-based modeling and validation of the intricate timing asp... more This paper presents a case study in UML-based modeling and validation of the intricate timing aspects arising in a small but complex component of the airborne Medium-Altitude Reconnaissance System produced by the Netherlands National Aerospace Laboratory. The purpose is to show how automata-based timing analysis and verification tools can be used by field engineers for solving isolated hard points in a complex real-time design, even if the press-button verification of entire systems remains a remote goal. We claim that the accessibility of such tools is largely improved by the use of an UML profile with intuitive features for modeling timing and related properties.
A tool for symbolic program verification and abstraction
Lecture Notes in Computer Science, 1993
We give the description of a verification tool taking boolean programs of guarded commandsas inpu... more We give the description of a verification tool taking boolean programs of guarded commandsas input; internal representation of programs are sets of Binary Decision Diagrams(BDD) (one for each guarded command). It allows to construct an abstract program of thesame form obtained using an abstraction relation given by a boolean expression on "concrete"and "abstract" variables. The tool allows the verification of
ABSTRACT This paper presents an overview on the IF toolset which is an environment for modelling ... more ABSTRACT This paper presents an overview on the IF toolset which is an environment for modelling and validation of heterogeneous real-time systems. The toolset is built upon a rich formalism, the IF notation, allowing structured automata-based system representations. Moreover, the IF notation is expressive enough to support real-time primitives and extensions of high-level modelling languages such as SDL and UML by means of structure preserving mappings. The core part of the IF toolset consists of a syntactic transformation component and an open exploration platform. The syntactic transformation component provides language level access to IF descriptions and has been used to implement static analysis and optimisation techniques. The exploration platform gives access to the graph of possible executions. It has been connected to different state-of-the-art model-checking and test-case generation tools. A methodology for the use of the toolset is presented at hand of a case study concerning the Ariane-5 Flight Program for which both an SDL and a UML model have been validated.
Controlling concurrent systems to impose some global invariant, is an undecidable problem. One ca... more Controlling concurrent systems to impose some global invariant, is an undecidable problem. One can gain decidability at the expense of reducing concurrency. Even under this flexible design assumption, the synthesis problem remains highly intractable. One practical method for designing controllers is based on checking knowledge properties upon which the processes can make their decisions whether to allow or block transitions. A major deficiency of this synthesis method is in calculating the knowledge based on the given system that we want to control, and not on the resulted system. The original system has less knowledge, and as a result, we may introduce far more synchronization than needed. In this paper we show techniques to reduce this overhead.
IF: A Validation Environment for Timed Asynchronous Systems
Lecture Notes in Computer Science, 2000
Formal validation of distributed systems relies on several specification formalisms (such as the ... more Formal validation of distributed systems relies on several specification formalisms (such as the international standards lotos [15] or sdl [16]), and it requires different kinds of tools to cover the whole development process. Presently, a wide range of tools are available, either ...
We present work of a project for the improvement of a speci cation/validation toolbox integrating... more We present work of a project for the improvement of a speci cation/validation toolbox integrating a commercial toolset Objectgeode and di erent validation tools such as the veri cation tool cadp and the test sequence generator tgv.
Abstract. In this paper we propose some extensions necessary to en-able the specification and des... more Abstract. In this paper we propose some extensions necessary to en-able the specification and description language Sdl to become a more appropriate formalism for the design of real-time and embedded systems. The extensions we envisage concern both roles of Sdl: first, in ...
Modeling and Validation of a Software Architecture for the Ariane-5 Launcher
Lecture Notes in Computer Science, 2006
... In this section, we discuss briefly the concepts and we give an example of how they are put t... more ... In this section, we discuss briefly the concepts and we give an example of how they are put to work in the Ariane-5 model. ... An anomaly on the Vulcain ignition corresponds, in our modeling of the en-vironment, to a Valve object entering the Failed Open state. ...
What are the limits of model checking methods for the verification of real life protocols?
Lecture Notes in Computer Science, 1990
... some properties assume that all messages sent by some process are distinguishable, which requ... more ... some properties assume that all messages sent by some process are distinguishable, which requires an infinite set of message identifications if infinite execution sequences ... procedure, that effectively blocks all further communications in the affected group of stations ...
Spin [9] is a model checker for the verification of distributed systems software. The tool is fre... more Spin [9] is a model checker for the verification of distributed systems software. The tool is freely distributed, and often described as one of the most widely used verification systems. The Advanced Spin Tutorial is a sequel to [7] and is targeted towards intermediate to ...
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Papers by Susanne Graf