Team Cassis

Overall Objectives
Scientific Foundations
Application Domains
New Results
Contracts and Grants with Industry
Other Grants and Activities

Section: New Results

Model-based Verification and Testing

Regular Model-Checking on infinite Words

Keywords : Parametric systems, regular languages, reachability.

Participant : P.-C. Héam.

The regular model checking techniques use regular languages for reachability analysis: states of the system are represented by finite automata or regular expressions and actions are modelized by transducers or rewriting rules on words.

In previous work [73] , [72] , we have studied the language of finite words reachable from a given language by using the transitive closure of a semi-commutation relation, i.e. a finite union of rewriting rules

In [Oops!] , we extend this approach to infinite words : we show how to adapt the algorithms of  [73] in order to handle regular $ \omega$ -languages accepted by Büchi automata.

Model-based Testing

Participants : Fabrice Bouquet, Thibaut Brocard, Jean-François Couchot, Frédéric Dadeau, Stéphane Debricon, Alain Giorgetti, Adrien de Kermadec, Vincent Pretre.

Our model-based testing approach has been extended in three ways: i) for modelling support, ii)for security, and iii) for distributed applications.

By essence, Model-based testing is bounded to use enumerated data structures. On the other hand, formal modeling often involves parameterized data structures in order e.g. to test several implementation variants or to abstract away from irrelevant details. Hence the validation engineer has sooner or later to instantiate these parameters. Recent results in instantiation-based theorem proving show that it is often possible to guess a small instantiated formula that is equisatisfiable with the quantified one. Following this approach, we provide a formal characterization of the most general instantiation of the system. In  [Oops!] we address the problem of instantiating data structures in formal models intended to be used in a model-based testing approach.

We have introduced an original model-based testing approach that takes a UML behavioural view of the system under test and automatically generates test cases and executable test scripts according to model coverage criteria  [Oops!] .

We are investigating testing techniques that exercise security properties derived from a security policy. For that we combine a functional model with a second model that formalizes a part of the security policy. Tests are computed from the security properties with the formal functional model as an oracle. This work has been performed in the project POSÉ and has been used to validate some security properties of an airport model  [Oops!] .

In order to validate web service applications, we explore model based testing methodologies. The results of tests are used to compute a mark that qualify the quality of web services operations. This solution is then integrated in a validation framework based on an UDDI server. In this framework, web services are tested when they are declared to the UDDI server, and the obtained marks are supplied to customers seeking for services  [Oops!] .


Logo Inria