add TM1 Server to Performance Modeler

1. Log in to Cognos TM1 Application Web.
2. On the toolbar, click the Administer Cognos TM1 Applications button .
   The IBM Cognos TM1 Applications Configuration page opens
3. In the Server Names section, click Add.
   The Add Server dialog box opens.
4. Enter the following values:
   • Admin Host – Specify the computer name or IP address of the Admin Host on which the Cognos TM1 Admin Server is running.

     Click the Refresh button to update the Server Name list with the available servers for the Admin Host you entered.

   • Server Name – Select a TM1 Server to use with Cognos TM1 Application Web. For example: Planning Sample. 
5. Click OK.

   If you receive a warning message about the configuration of the TM1 Server, make a note of the warnings and then click Close to continue. For more information, see Configuring a TM1 Server to work with TM1 Application Web.

   The Admin Host and TM1 Server name you entered are added to the Server Names section.
6. To add more servers, click Add and repeat the steps. 
7. When you are finished adding TM1 Servers, click OK on the IBM Cognos TM1 Applications Configuration page.

https://www.ibm.com/docs/en/planning-analytics/2.0.0?topic=tasaic-configuring-tm1-application-web-use-multiple-tm1-servers