Dependency Graphs to Boost the Verification of SysML Models
Résumé
Model-Based Systems Engineering has often been associated with the
Systems Modeling Language. Several SysML tools offer formal verification ca-
pabilities, and therefore enable early detection of design errors in the life cycle
of systems. Model-checking is a common formal verification approach used to
assess the satisfiability of properties. Thus, a SysML model and a property can
be injected into a model-checker returning a true/false result. A drawback of this
approach is that the entire SysML model is used for the verification, even if the
property targets a sub-system of the model. In this paper, it is suggested to rely on
dependency graphs to avoid applying model checking to the entire system when
only a subset of the latter needs to be taken into account. We formalize SysML
models and properties, then we present new algorithms to generate and reduce de-
pendency graphs, so as to perform verification on reduced models. A case study
on Time-Sensitive Networking is used to demonstrate the efficiency and limits of
this approach. The algorithms described in the paper are fully implemented by the
free software TTool. Our method enables an improvement in run time between
3% and 90% depending on the state space to be traversed to verify the property.