Solving the Model

In this example we are interested in the steady state behavior of the system. To solve the model, click on the Analytical Model Solution button. Choose the Exact or Iterative Methods. In this case, you can choose any method.

After this step, we are able to calculate the measures of interest. For example the user can obtain the of the number of active sources, and the probability that the number of on-off sources is greater than a given value conditioned on the queue being at its maximum value.

Choose the Measures of Interest module. Then choose the , select the state variable active_sources, and click on Plot to obtain the first measure above.

Now assume that you want to solve this model by simulation. Please refer to chapter and the section on messages and events to learn about the event execution process. The model above can be immediately simulated. Recall that an enabled event $E$ is not re-sampled if another event triggers and $E$ remains enabled in the new state. The following situation occurs in the example above. Assume that only one source is active. Then 2 events of the object source can trigger in this state and 2 samples are in the event list. Assume that the event corresponding to the disabling of a source triggers. The event corresponding to enabling a source remains in the event list. However, this event was generated with rate $(\texttt{active\_sources}-1) \times \alpha$. When it triggers, the new state will be one active source and therefore no event with rate $\texttt{active\_sources} \times \alpha$ will ever be generated. The user should follow the steps in chapter to build a model that generates new samples of events after an action (even if the events remain enabled), and compare the resulting models.