Refer to article to How to add/edit/delete System?
Refer to article to How to add/edit/delete Execution Configuration?
1. Click on machine drop down field in creating an execution configuration page.
2. Select system title from drop down list.
3. Click on create Button. Machine and platform saved along with execution configuration information. Displayed in details page.
4. Added machine list can see in execution details page under environment.
5. If you want to edit machine go to execution configuration edit page.
6. If you want to change the machine, select from drop down list and click on update.