Running an impact simulation

Before you begin

• Before using CMDB Impact Simulator, you should have an impact model of the CIs in place. 
  For information see, Creating-and-testing-impact-models.
• To access the CMDB Impact Simulator through CMDB Portal, you must configure the default web path of the Mid Tier server in AR System Administration Console. For information, see Configuring-the-default-web-path-of-the-Mid-Tier-server-in-AR-System-Administration-Console

Impact states

When you create a simulation, you can specify an impact state for each CI in the simulation. 

When you run a simulation, CMDB Impact Simulator uses these states and the impact relationships defined between CIs to predict the corresponding impact on the CIs that it represents. For example, a simulation that includes a server with an impact state of Unavailable might return several related CIs that are predicted to be unavailable as a result of the unavailable server. However, a server with an impact state of Impaired in the same simulation might return impacted CIs that are predicted to be only slightly impaired.

The results of the impact simulation can help you prioritize which issues to address first as a result of the simulated changes.

For example, a simulation might reveal that if a server were to fail, email and payroll services may be unavailable. The computed priority for these services helps you decide the service that must be restored first.

To run an impact simulation

1. In CMDB Portal, select Atrium Core > Simulate Impact to launch the CMDB Impact Simulator in the AIS:Main AR System form.

2. In CMDB Impact Simulator, click Add CI to add a CI for which you want to simulate the impact.

   Important

   If the search widget does not load, refresh the web page and click Add CI.

3. In the Search dialog box, run a query that returns the CIs you want to include in the simulation.

4. From the results list, select one or more CIs, and then click OK. 
   The selected CIs appear in the CIs for Simulation section.
   

   Important

   The sorting option is not available for the Name column because the column length is changed out-of-the-box to accommodate modifications. To enable sorting for the Name column in the AIS:Main form, use the Centralized Configuration to update the CCS parameter arsystem.table_column_max_sort_size to a value greater than 255 characters. After you make this change, the Name column displays the sorting icon in the AIS:Main form. 

   For more information about using the Centralized Configurations, see Impact-Simulator-configuration-settings.

5. Select a CI, and then select an impact state from the list.
   
   
   
6. Repeat this step until every row in the CIs for Simulation section has the impact state that you want to simulate.
7. Click Simulate Impact.
   View the results of the simulation in a topology view or a table view.
   By default, the table view is displayed.
   
8. To view the results in a topology view, click the Results in Topology tab. 
   The topology view is as shown in the following figure:
   
9. To view the legend, click Indicators.

10. To view the service model graph in CMDB Explorer, click View in Explorer.
    This view is useful for large service models when the graph may not fit in the topology view.

    Important

    • When you click View in Explorer to view a service model graph, do not use the Edit Mode feature to create new CIs in that service model.
    • When you run an impact simulation, the dataset tab in CMDB Explorer displays the name Impact Simulation as shown in the following image:
      
      

To trigger custom actions after simulation is complete

When you run an impact simulation, a simulation ID is generated on the CMDB:Activities form in the Data field. You can create filters on the CMDB:Activities form by using this ID and initiate custom actions in other applications without any delay. The Execution Action for the filter should be set to Merge.

To save the simulation

1. To save a simulation, click Save Simulation.
   
   
   
2. In the Save Simulation dialog box, enter a name and description for the simulation.
3. Enter a description of the simulation.
4. Click Save.

To load a saved impact simulation

If you have saved an impact simulation, perform the following steps to load that simulation and refresh the simulation results.

1. To view a previously saved simulation, click Load Simulation.
   
   
   
2. In the Saved Simulation dialog box, select a saved simulation.
3. Click Load.
   The simulation is loaded with its configuration items (CIs), simulated states, and the results from the last time that the simulation was saved.
   If the impact model has changed, or the relationships between CIs in the data model have changed, the saved simulation results might not be accurate. 
   Running the simulation again makes sure that the results are current.
4. Click Simulate Impact to refresh the results table.

Where to go from here

• Comparing-impact-simulations