UML Modelling and Performance Analysis

Modern distributed software applications generally operate in complex and heterogeneous computing environments (like the World Wide Web). Different paradigms (client-server, mobility based, etc.) have been suggested and adopted to cope with the complexity of designing the software architecture of distributed applications for such environments, and deciding the "best" paradigm is a typical choice to be made in the very early software design phases. Several factors should drive this choice, one of them being the impact of the adopted paradigm on the application performance. Within this framework, the contribute of this paper is twofold: we suggest an extension of UML to best modeling the possible adoption of mobility-based paradigms in the software architecture of an application; we introduce a complete methodology that, starting from a software architecture described using this extended notation, generates a performance model (namely a Markov Reward or Decision Process) that allows the designer to evaluate the convenience of introducing logical mobility into a software application.