Mapping annotated sequence diagram to a Petri net notation for reliability evaluation

The quality of software architecture has a great influence on achieving non-functional requirements to the software system. In this paper, we propose an approach based on Petri nets models for reliability prediction of software systems at the software architecture level, specified by UML. UML lacks a formal semantics and hence it is not possible to apply, directly, mathematical techniques on UML models for reliability evaluation. To reach this goal we propose an automatic translation of UML Diagrams into Petri Nets. In this paper we study the use of Sequence Diagrams for the reliability evaluation of software architecture. Starting from annotated UML sequence diagrams we derive a reliability models based on Petri nets. The UML model is annotated according to the UML profile for Quality of Service and Fault Tolerance. The proposed algorithm translates the annotated UML specification into Petri net reliability models, which can then be analyzed using standard techniques. Reliability results are feedback at the software architecture level in the UML diagrams.