Validating timed UML models by simulation and verification

Abstract

Abstract. We present in this paper a technique and a tool for validating operational UML models by simulation and verification of dynamic properties. With respect to language coverage, our approach takes into consideration most of the structural and behavioral characteristics of classes and their interplay. We tackle issues like the combination of operations, state machines, inheritance and polymorphism, with a particular run-tocompletion and concurrency semantics. This is an important point, as many previous approaches applying model checking to UML put limiting conditions on the models. The UML dialect considered here also includes a set of extensions for expressing timing, which were defined in detail in [18]. For writing properties about models, we introduce UML observer objects. Observers are both easy to use -they reuse existing concepts of UML, and powerful -they are equivalent to linear temporal logic. Our approach is implemented by a tool built on top of an XMI repository. The tool is connected to several commercial and non-commercial UML editors, and to other model checking tools.

Modeling and Validation of a Software Architecture for the Ariane-5 Launcher

“…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. More detail on observers can be found in [18].…”

“…To prove their correctness, the cyclic GNC part has been abstracted by eliminating all the internal behavior and by sending messages (flight phase change commands) at arbitrary moments rather than at the precise time points computed by the concrete GNC. This represents clearly an abstraction and it was sufficient to show the satisfaction of all the properties of the asynchronous part (see [18,3] for an older experience concerning this part). Note also that such an abstraction can in principle be constructed automatically.…”

“…We discuss the verification of both functional and scheduling-related requirements with the IFx toolset [18] which implements the profile.…”

“…IFx 2 [18] is a toolset providing simulation and model-checking functionalities for Omega UML models. It is built on top of the IF environment [4], and provides a compiler of UML models to IF specifications.…”

“…In order to scale to complex models, IF supports optimization and abstraction in several ways: by "exact" static optimizations (like dead variable factorization and dead code elimination), by partial-order reduction, by data abstraction (static slicing). More details can be found in [18].…”