Testing Your Entries in Systems.xml 
Use
Once you have maintained entries in the systems.xml file for your component systems, you can test your entries for each system using a test function provided in the Enterprise Portal.
This test function allows you to test for each system whether the correct entries are maintained to start applications such as SAP transactions, BW Web applications, or Internet Application Components. In addition it tests the connection to the Internet Transaction Server and Web Application Server of the system.
Prerequisites
You have maintained entries for your component systems in the systems.xml file and uploaded the systems.xml file into the PCD as described in
Editing System Landscape Files.Procedure
The test function is available under System Test in the list of functions on the left-hand side.
The test results are displayed in the view area on the right-hand side.