**3. Performance modeling framework**

We already mentioned our main objective in the previous section that will be presented broadly in this section. In order to achieve the main objective, we need to follow an engineering approach that will accelerate the distributed software system development process. We also need to define the method that will be accounted for evaluating the system performance. We limit ourselves to methods targeting system development process using the standards of UML (Unified Modeling Languages) [9]. In the evaluation side we limit ourselves to methods that will analytically solve our problem using the technique SPN (Stochastic Petri Nets). This section mainly presents these two main techniques and also focuses on their properties that will be utilized to design our performance modeling framework.
